diff --git "a/env-llmeval/lib/python3.10/site-packages/pandas/core/indexes/multi.py" "b/env-llmeval/lib/python3.10/site-packages/pandas/core/indexes/multi.py" new file mode 100644--- /dev/null +++ "b/env-llmeval/lib/python3.10/site-packages/pandas/core/indexes/multi.py" @@ -0,0 +1,4157 @@ +from __future__ import annotations + +from collections.abc import ( + Collection, + Generator, + Hashable, + Iterable, + Sequence, +) +from functools import wraps +from sys import getsizeof +from typing import ( + TYPE_CHECKING, + Any, + Callable, + Literal, + cast, +) +import warnings + +import numpy as np + +from pandas._config import get_option + +from pandas._libs import ( + algos as libalgos, + index as libindex, + lib, +) +from pandas._libs.hashtable import duplicated +from pandas._typing import ( + AnyAll, + AnyArrayLike, + Axis, + DropKeep, + DtypeObj, + F, + IgnoreRaise, + IndexLabel, + Scalar, + Self, + Shape, + npt, +) +from pandas.compat.numpy import function as nv +from pandas.errors import ( + InvalidIndexError, + PerformanceWarning, + UnsortedIndexError, +) +from pandas.util._decorators import ( + Appender, + cache_readonly, + doc, +) +from pandas.util._exceptions import find_stack_level + +from pandas.core.dtypes.cast import coerce_indexer_dtype +from pandas.core.dtypes.common import ( + ensure_int64, + ensure_platform_int, + is_hashable, + is_integer, + is_iterator, + is_list_like, + is_object_dtype, + is_scalar, + pandas_dtype, +) +from pandas.core.dtypes.dtypes import ( + CategoricalDtype, + ExtensionDtype, +) +from pandas.core.dtypes.generic import ( + ABCDataFrame, + ABCSeries, +) +from pandas.core.dtypes.inference import is_array_like +from pandas.core.dtypes.missing import ( + array_equivalent, + isna, +) + +import pandas.core.algorithms as algos +from pandas.core.array_algos.putmask import validate_putmask +from pandas.core.arrays import ( + Categorical, + ExtensionArray, +) +from pandas.core.arrays.categorical import ( + factorize_from_iterables, + recode_for_categories, +) +import pandas.core.common as com +from pandas.core.construction import sanitize_array +import pandas.core.indexes.base as ibase +from pandas.core.indexes.base import ( + Index, + _index_shared_docs, + ensure_index, + get_unanimous_names, +) +from pandas.core.indexes.frozen import FrozenList +from pandas.core.ops.invalid import make_invalid_op +from pandas.core.sorting import ( + get_group_index, + lexsort_indexer, +) + +from pandas.io.formats.printing import ( + get_adjustment, + pprint_thing, +) + +if TYPE_CHECKING: + from pandas import ( + CategoricalIndex, + DataFrame, + Series, + ) + +_index_doc_kwargs = dict(ibase._index_doc_kwargs) +_index_doc_kwargs.update( + {"klass": "MultiIndex", "target_klass": "MultiIndex or list of tuples"} +) + + +class MultiIndexUIntEngine(libindex.BaseMultiIndexCodesEngine, libindex.UInt64Engine): + """ + This class manages a MultiIndex by mapping label combinations to positive + integers. + """ + + _base = libindex.UInt64Engine + + def _codes_to_ints(self, codes): + """ + Transform combination(s) of uint64 in one uint64 (each), in a strictly + monotonic way (i.e. respecting the lexicographic order of integer + combinations): see BaseMultiIndexCodesEngine documentation. + + Parameters + ---------- + codes : 1- or 2-dimensional array of dtype uint64 + Combinations of integers (one per row) + + Returns + ------- + scalar or 1-dimensional array, of dtype uint64 + Integer(s) representing one combination (each). + """ + # Shift the representation of each level by the pre-calculated number + # of bits: + codes <<= self.offsets + + # Now sum and OR are in fact interchangeable. This is a simple + # composition of the (disjunct) significant bits of each level (i.e. + # each column in "codes") in a single positive integer: + if codes.ndim == 1: + # Single key + return np.bitwise_or.reduce(codes) + + # Multiple keys + return np.bitwise_or.reduce(codes, axis=1) + + +class MultiIndexPyIntEngine(libindex.BaseMultiIndexCodesEngine, libindex.ObjectEngine): + """ + This class manages those (extreme) cases in which the number of possible + label combinations overflows the 64 bits integers, and uses an ObjectEngine + containing Python integers. + """ + + _base = libindex.ObjectEngine + + def _codes_to_ints(self, codes): + """ + Transform combination(s) of uint64 in one Python integer (each), in a + strictly monotonic way (i.e. respecting the lexicographic order of + integer combinations): see BaseMultiIndexCodesEngine documentation. + + Parameters + ---------- + codes : 1- or 2-dimensional array of dtype uint64 + Combinations of integers (one per row) + + Returns + ------- + int, or 1-dimensional array of dtype object + Integer(s) representing one combination (each). + """ + # Shift the representation of each level by the pre-calculated number + # of bits. Since this can overflow uint64, first make sure we are + # working with Python integers: + codes = codes.astype("object") << self.offsets + + # Now sum and OR are in fact interchangeable. This is a simple + # composition of the (disjunct) significant bits of each level (i.e. + # each column in "codes") in a single positive integer (per row): + if codes.ndim == 1: + # Single key + return np.bitwise_or.reduce(codes) + + # Multiple keys + return np.bitwise_or.reduce(codes, axis=1) + + +def names_compat(meth: F) -> F: + """ + A decorator to allow either `name` or `names` keyword but not both. + + This makes it easier to share code with base class. + """ + + @wraps(meth) + def new_meth(self_or_cls, *args, **kwargs): + if "name" in kwargs and "names" in kwargs: + raise TypeError("Can only provide one of `names` and `name`") + if "name" in kwargs: + kwargs["names"] = kwargs.pop("name") + + return meth(self_or_cls, *args, **kwargs) + + return cast(F, new_meth) + + +class MultiIndex(Index): + """ + A multi-level, or hierarchical, index object for pandas objects. + + Parameters + ---------- + levels : sequence of arrays + The unique labels for each level. + codes : sequence of arrays + Integers for each level designating which label at each location. + sortorder : optional int + Level of sortedness (must be lexicographically sorted by that + level). + names : optional sequence of objects + Names for each of the index levels. (name is accepted for compat). + copy : bool, default False + Copy the meta-data. + verify_integrity : bool, default True + Check that the levels/codes are consistent and valid. + + Attributes + ---------- + names + levels + codes + nlevels + levshape + dtypes + + Methods + ------- + from_arrays + from_tuples + from_product + from_frame + set_levels + set_codes + to_frame + to_flat_index + sortlevel + droplevel + swaplevel + reorder_levels + remove_unused_levels + get_level_values + get_indexer + get_loc + get_locs + get_loc_level + drop + + See Also + -------- + MultiIndex.from_arrays : Convert list of arrays to MultiIndex. + MultiIndex.from_product : Create a MultiIndex from the cartesian product + of iterables. + MultiIndex.from_tuples : Convert list of tuples to a MultiIndex. + MultiIndex.from_frame : Make a MultiIndex from a DataFrame. + Index : The base pandas Index type. + + Notes + ----- + See the `user guide + `__ + for more. + + Examples + -------- + A new ``MultiIndex`` is typically constructed using one of the helper + methods :meth:`MultiIndex.from_arrays`, :meth:`MultiIndex.from_product` + and :meth:`MultiIndex.from_tuples`. For example (using ``.from_arrays``): + + >>> arrays = [[1, 1, 2, 2], ['red', 'blue', 'red', 'blue']] + >>> pd.MultiIndex.from_arrays(arrays, names=('number', 'color')) + MultiIndex([(1, 'red'), + (1, 'blue'), + (2, 'red'), + (2, 'blue')], + names=['number', 'color']) + + See further examples for how to construct a MultiIndex in the doc strings + of the mentioned helper methods. + """ + + _hidden_attrs = Index._hidden_attrs | frozenset() + + # initialize to zero-length tuples to make everything work + _typ = "multiindex" + _names: list[Hashable | None] = [] + _levels = FrozenList() + _codes = FrozenList() + _comparables = ["names"] + + sortorder: int | None + + # -------------------------------------------------------------------- + # Constructors + + def __new__( + cls, + levels=None, + codes=None, + sortorder=None, + names=None, + dtype=None, + copy: bool = False, + name=None, + verify_integrity: bool = True, + ) -> Self: + # compat with Index + if name is not None: + names = name + if levels is None or codes is None: + raise TypeError("Must pass both levels and codes") + if len(levels) != len(codes): + raise ValueError("Length of levels and codes must be the same.") + if len(levels) == 0: + raise ValueError("Must pass non-zero number of levels/codes") + + result = object.__new__(cls) + result._cache = {} + + # we've already validated levels and codes, so shortcut here + result._set_levels(levels, copy=copy, validate=False) + result._set_codes(codes, copy=copy, validate=False) + + result._names = [None] * len(levels) + if names is not None: + # handles name validation + result._set_names(names) + + if sortorder is not None: + result.sortorder = int(sortorder) + else: + result.sortorder = sortorder + + if verify_integrity: + new_codes = result._verify_integrity() + result._codes = new_codes + + result._reset_identity() + result._references = None + + return result + + def _validate_codes(self, level: list, code: list): + """ + Reassign code values as -1 if their corresponding levels are NaN. + + Parameters + ---------- + code : list + Code to reassign. + level : list + Level to check for missing values (NaN, NaT, None). + + Returns + ------- + new code where code value = -1 if it corresponds + to a level with missing values (NaN, NaT, None). + """ + null_mask = isna(level) + if np.any(null_mask): + # error: Incompatible types in assignment + # (expression has type "ndarray[Any, dtype[Any]]", + # variable has type "List[Any]") + code = np.where(null_mask[code], -1, code) # type: ignore[assignment] + return code + + def _verify_integrity( + self, + codes: list | None = None, + levels: list | None = None, + levels_to_verify: list[int] | range | None = None, + ): + """ + Parameters + ---------- + codes : optional list + Codes to check for validity. Defaults to current codes. + levels : optional list + Levels to check for validity. Defaults to current levels. + levels_to_validate: optional list + Specifies the levels to verify. + + Raises + ------ + ValueError + If length of levels and codes don't match, if the codes for any + level would exceed level bounds, or there are any duplicate levels. + + Returns + ------- + new codes where code value = -1 if it corresponds to a + NaN level. + """ + # NOTE: Currently does not check, among other things, that cached + # nlevels matches nor that sortorder matches actually sortorder. + codes = codes or self.codes + levels = levels or self.levels + if levels_to_verify is None: + levels_to_verify = range(len(levels)) + + if len(levels) != len(codes): + raise ValueError( + "Length of levels and codes must match. NOTE: " + "this index is in an inconsistent state." + ) + codes_length = len(codes[0]) + for i in levels_to_verify: + level = levels[i] + level_codes = codes[i] + + if len(level_codes) != codes_length: + raise ValueError( + f"Unequal code lengths: {[len(code_) for code_ in codes]}" + ) + if len(level_codes) and level_codes.max() >= len(level): + raise ValueError( + f"On level {i}, code max ({level_codes.max()}) >= length of " + f"level ({len(level)}). NOTE: this index is in an " + "inconsistent state" + ) + if len(level_codes) and level_codes.min() < -1: + raise ValueError(f"On level {i}, code value ({level_codes.min()}) < -1") + if not level.is_unique: + raise ValueError( + f"Level values must be unique: {list(level)} on level {i}" + ) + if self.sortorder is not None: + if self.sortorder > _lexsort_depth(self.codes, self.nlevels): + raise ValueError( + "Value for sortorder must be inferior or equal to actual " + f"lexsort_depth: sortorder {self.sortorder} " + f"with lexsort_depth {_lexsort_depth(self.codes, self.nlevels)}" + ) + + result_codes = [] + for i in range(len(levels)): + if i in levels_to_verify: + result_codes.append(self._validate_codes(levels[i], codes[i])) + else: + result_codes.append(codes[i]) + + new_codes = FrozenList(result_codes) + return new_codes + + @classmethod + def from_arrays( + cls, + arrays, + sortorder: int | None = None, + names: Sequence[Hashable] | Hashable | lib.NoDefault = lib.no_default, + ) -> MultiIndex: + """ + Convert arrays to MultiIndex. + + Parameters + ---------- + arrays : list / sequence of array-likes + Each array-like gives one level's value for each data point. + len(arrays) is the number of levels. + sortorder : int or None + Level of sortedness (must be lexicographically sorted by that + level). + names : list / sequence of str, optional + Names for the levels in the index. + + Returns + ------- + MultiIndex + + See Also + -------- + MultiIndex.from_tuples : Convert list of tuples to MultiIndex. + MultiIndex.from_product : Make a MultiIndex from cartesian product + of iterables. + MultiIndex.from_frame : Make a MultiIndex from a DataFrame. + + Examples + -------- + >>> arrays = [[1, 1, 2, 2], ['red', 'blue', 'red', 'blue']] + >>> pd.MultiIndex.from_arrays(arrays, names=('number', 'color')) + MultiIndex([(1, 'red'), + (1, 'blue'), + (2, 'red'), + (2, 'blue')], + names=['number', 'color']) + """ + error_msg = "Input must be a list / sequence of array-likes." + if not is_list_like(arrays): + raise TypeError(error_msg) + if is_iterator(arrays): + arrays = list(arrays) + + # Check if elements of array are list-like + for array in arrays: + if not is_list_like(array): + raise TypeError(error_msg) + + # Check if lengths of all arrays are equal or not, + # raise ValueError, if not + for i in range(1, len(arrays)): + if len(arrays[i]) != len(arrays[i - 1]): + raise ValueError("all arrays must be same length") + + codes, levels = factorize_from_iterables(arrays) + if names is lib.no_default: + names = [getattr(arr, "name", None) for arr in arrays] + + return cls( + levels=levels, + codes=codes, + sortorder=sortorder, + names=names, + verify_integrity=False, + ) + + @classmethod + @names_compat + def from_tuples( + cls, + tuples: Iterable[tuple[Hashable, ...]], + sortorder: int | None = None, + names: Sequence[Hashable] | Hashable | None = None, + ) -> MultiIndex: + """ + Convert list of tuples to MultiIndex. + + Parameters + ---------- + tuples : list / sequence of tuple-likes + Each tuple is the index of one row/column. + sortorder : int or None + Level of sortedness (must be lexicographically sorted by that + level). + names : list / sequence of str, optional + Names for the levels in the index. + + Returns + ------- + MultiIndex + + See Also + -------- + MultiIndex.from_arrays : Convert list of arrays to MultiIndex. + MultiIndex.from_product : Make a MultiIndex from cartesian product + of iterables. + MultiIndex.from_frame : Make a MultiIndex from a DataFrame. + + Examples + -------- + >>> tuples = [(1, 'red'), (1, 'blue'), + ... (2, 'red'), (2, 'blue')] + >>> pd.MultiIndex.from_tuples(tuples, names=('number', 'color')) + MultiIndex([(1, 'red'), + (1, 'blue'), + (2, 'red'), + (2, 'blue')], + names=['number', 'color']) + """ + if not is_list_like(tuples): + raise TypeError("Input must be a list / sequence of tuple-likes.") + if is_iterator(tuples): + tuples = list(tuples) + tuples = cast(Collection[tuple[Hashable, ...]], tuples) + + # handling the empty tuple cases + if len(tuples) and all(isinstance(e, tuple) and not e for e in tuples): + codes = [np.zeros(len(tuples))] + levels = [Index(com.asarray_tuplesafe(tuples, dtype=np.dtype("object")))] + return cls( + levels=levels, + codes=codes, + sortorder=sortorder, + names=names, + verify_integrity=False, + ) + + arrays: list[Sequence[Hashable]] + if len(tuples) == 0: + if names is None: + raise TypeError("Cannot infer number of levels from empty list") + # error: Argument 1 to "len" has incompatible type "Hashable"; + # expected "Sized" + arrays = [[]] * len(names) # type: ignore[arg-type] + elif isinstance(tuples, (np.ndarray, Index)): + if isinstance(tuples, Index): + tuples = np.asarray(tuples._values) + + arrays = list(lib.tuples_to_object_array(tuples).T) + elif isinstance(tuples, list): + arrays = list(lib.to_object_array_tuples(tuples).T) + else: + arrs = zip(*tuples) + arrays = cast(list[Sequence[Hashable]], arrs) + + return cls.from_arrays(arrays, sortorder=sortorder, names=names) + + @classmethod + def from_product( + cls, + iterables: Sequence[Iterable[Hashable]], + sortorder: int | None = None, + names: Sequence[Hashable] | Hashable | lib.NoDefault = lib.no_default, + ) -> MultiIndex: + """ + Make a MultiIndex from the cartesian product of multiple iterables. + + Parameters + ---------- + iterables : list / sequence of iterables + Each iterable has unique labels for each level of the index. + sortorder : int or None + Level of sortedness (must be lexicographically sorted by that + level). + names : list / sequence of str, optional + Names for the levels in the index. + If not explicitly provided, names will be inferred from the + elements of iterables if an element has a name attribute. + + Returns + ------- + MultiIndex + + See Also + -------- + MultiIndex.from_arrays : Convert list of arrays to MultiIndex. + MultiIndex.from_tuples : Convert list of tuples to MultiIndex. + MultiIndex.from_frame : Make a MultiIndex from a DataFrame. + + Examples + -------- + >>> numbers = [0, 1, 2] + >>> colors = ['green', 'purple'] + >>> pd.MultiIndex.from_product([numbers, colors], + ... names=['number', 'color']) + MultiIndex([(0, 'green'), + (0, 'purple'), + (1, 'green'), + (1, 'purple'), + (2, 'green'), + (2, 'purple')], + names=['number', 'color']) + """ + from pandas.core.reshape.util import cartesian_product + + if not is_list_like(iterables): + raise TypeError("Input must be a list / sequence of iterables.") + if is_iterator(iterables): + iterables = list(iterables) + + codes, levels = factorize_from_iterables(iterables) + if names is lib.no_default: + names = [getattr(it, "name", None) for it in iterables] + + # codes are all ndarrays, so cartesian_product is lossless + codes = cartesian_product(codes) + return cls(levels, codes, sortorder=sortorder, names=names) + + @classmethod + def from_frame( + cls, + df: DataFrame, + sortorder: int | None = None, + names: Sequence[Hashable] | Hashable | None = None, + ) -> MultiIndex: + """ + Make a MultiIndex from a DataFrame. + + Parameters + ---------- + df : DataFrame + DataFrame to be converted to MultiIndex. + sortorder : int, optional + Level of sortedness (must be lexicographically sorted by that + level). + names : list-like, optional + If no names are provided, use the column names, or tuple of column + names if the columns is a MultiIndex. If a sequence, overwrite + names with the given sequence. + + Returns + ------- + MultiIndex + The MultiIndex representation of the given DataFrame. + + See Also + -------- + MultiIndex.from_arrays : Convert list of arrays to MultiIndex. + MultiIndex.from_tuples : Convert list of tuples to MultiIndex. + MultiIndex.from_product : Make a MultiIndex from cartesian product + of iterables. + + Examples + -------- + >>> df = pd.DataFrame([['HI', 'Temp'], ['HI', 'Precip'], + ... ['NJ', 'Temp'], ['NJ', 'Precip']], + ... columns=['a', 'b']) + >>> df + a b + 0 HI Temp + 1 HI Precip + 2 NJ Temp + 3 NJ Precip + + >>> pd.MultiIndex.from_frame(df) + MultiIndex([('HI', 'Temp'), + ('HI', 'Precip'), + ('NJ', 'Temp'), + ('NJ', 'Precip')], + names=['a', 'b']) + + Using explicit names, instead of the column names + + >>> pd.MultiIndex.from_frame(df, names=['state', 'observation']) + MultiIndex([('HI', 'Temp'), + ('HI', 'Precip'), + ('NJ', 'Temp'), + ('NJ', 'Precip')], + names=['state', 'observation']) + """ + if not isinstance(df, ABCDataFrame): + raise TypeError("Input must be a DataFrame") + + column_names, columns = zip(*df.items()) + names = column_names if names is None else names + return cls.from_arrays(columns, sortorder=sortorder, names=names) + + # -------------------------------------------------------------------- + + @cache_readonly + def _values(self) -> np.ndarray: + # We override here, since our parent uses _data, which we don't use. + values = [] + + for i in range(self.nlevels): + index = self.levels[i] + codes = self.codes[i] + + vals = index + if isinstance(vals.dtype, CategoricalDtype): + vals = cast("CategoricalIndex", vals) + vals = vals._data._internal_get_values() + + if isinstance(vals.dtype, ExtensionDtype) or lib.is_np_dtype( + vals.dtype, "mM" + ): + vals = vals.astype(object) + + vals = np.asarray(vals) + vals = algos.take_nd(vals, codes, fill_value=index._na_value) + values.append(vals) + + arr = lib.fast_zip(values) + return arr + + @property + def values(self) -> np.ndarray: + return self._values + + @property + def array(self): + """ + Raises a ValueError for `MultiIndex` because there's no single + array backing a MultiIndex. + + Raises + ------ + ValueError + """ + raise ValueError( + "MultiIndex has no single backing array. Use " + "'MultiIndex.to_numpy()' to get a NumPy array of tuples." + ) + + @cache_readonly + def dtypes(self) -> Series: + """ + Return the dtypes as a Series for the underlying MultiIndex. + + Examples + -------- + >>> idx = pd.MultiIndex.from_product([(0, 1, 2), ('green', 'purple')], + ... names=['number', 'color']) + >>> idx + MultiIndex([(0, 'green'), + (0, 'purple'), + (1, 'green'), + (1, 'purple'), + (2, 'green'), + (2, 'purple')], + names=['number', 'color']) + >>> idx.dtypes + number int64 + color object + dtype: object + """ + from pandas import Series + + names = com.fill_missing_names([level.name for level in self.levels]) + return Series([level.dtype for level in self.levels], index=Index(names)) + + def __len__(self) -> int: + return len(self.codes[0]) + + @property + def size(self) -> int: + """ + Return the number of elements in the underlying data. + """ + # override Index.size to avoid materializing _values + return len(self) + + # -------------------------------------------------------------------- + # Levels Methods + + @cache_readonly + def levels(self) -> FrozenList: + """ + Levels of the MultiIndex. + + Levels refer to the different hierarchical levels or layers in a MultiIndex. + In a MultiIndex, each level represents a distinct dimension or category of + the index. + + To access the levels, you can use the levels attribute of the MultiIndex, + which returns a tuple of Index objects. Each Index object represents a + level in the MultiIndex and contains the unique values found in that + specific level. + + If a MultiIndex is created with levels A, B, C, and the DataFrame using + it filters out all rows of the level C, MultiIndex.levels will still + return A, B, C. + + Examples + -------- + >>> index = pd.MultiIndex.from_product([['mammal'], + ... ('goat', 'human', 'cat', 'dog')], + ... names=['Category', 'Animals']) + >>> leg_num = pd.DataFrame(data=(4, 2, 4, 4), index=index, columns=['Legs']) + >>> leg_num + Legs + Category Animals + mammal goat 4 + human 2 + cat 4 + dog 4 + + >>> leg_num.index.levels + FrozenList([['mammal'], ['cat', 'dog', 'goat', 'human']]) + + MultiIndex levels will not change even if the DataFrame using the MultiIndex + does not contain all them anymore. + See how "human" is not in the DataFrame, but it is still in levels: + + >>> large_leg_num = leg_num[leg_num.Legs > 2] + >>> large_leg_num + Legs + Category Animals + mammal goat 4 + cat 4 + dog 4 + + >>> large_leg_num.index.levels + FrozenList([['mammal'], ['cat', 'dog', 'goat', 'human']]) + """ + # Use cache_readonly to ensure that self.get_locs doesn't repeatedly + # create new IndexEngine + # https://github.com/pandas-dev/pandas/issues/31648 + result = [x._rename(name=name) for x, name in zip(self._levels, self._names)] + for level in result: + # disallow midx.levels[0].name = "foo" + level._no_setting_name = True + return FrozenList(result) + + def _set_levels( + self, + levels, + *, + level=None, + copy: bool = False, + validate: bool = True, + verify_integrity: bool = False, + ) -> None: + # This is NOT part of the levels property because it should be + # externally not allowed to set levels. User beware if you change + # _levels directly + if validate: + if len(levels) == 0: + raise ValueError("Must set non-zero number of levels.") + if level is None and len(levels) != self.nlevels: + raise ValueError("Length of levels must match number of levels.") + if level is not None and len(levels) != len(level): + raise ValueError("Length of levels must match length of level.") + + if level is None: + new_levels = FrozenList( + ensure_index(lev, copy=copy)._view() for lev in levels + ) + level_numbers = list(range(len(new_levels))) + else: + level_numbers = [self._get_level_number(lev) for lev in level] + new_levels_list = list(self._levels) + for lev_num, lev in zip(level_numbers, levels): + new_levels_list[lev_num] = ensure_index(lev, copy=copy)._view() + new_levels = FrozenList(new_levels_list) + + if verify_integrity: + new_codes = self._verify_integrity( + levels=new_levels, levels_to_verify=level_numbers + ) + self._codes = new_codes + + names = self.names + self._levels = new_levels + if any(names): + self._set_names(names) + + self._reset_cache() + + def set_levels( + self, levels, *, level=None, verify_integrity: bool = True + ) -> MultiIndex: + """ + Set new levels on MultiIndex. Defaults to returning new index. + + Parameters + ---------- + levels : sequence or list of sequence + New level(s) to apply. + level : int, level name, or sequence of int/level names (default None) + Level(s) to set (None for all levels). + verify_integrity : bool, default True + If True, checks that levels and codes are compatible. + + Returns + ------- + MultiIndex + + Examples + -------- + >>> idx = pd.MultiIndex.from_tuples( + ... [ + ... (1, "one"), + ... (1, "two"), + ... (2, "one"), + ... (2, "two"), + ... (3, "one"), + ... (3, "two") + ... ], + ... names=["foo", "bar"] + ... ) + >>> idx + MultiIndex([(1, 'one'), + (1, 'two'), + (2, 'one'), + (2, 'two'), + (3, 'one'), + (3, 'two')], + names=['foo', 'bar']) + + >>> idx.set_levels([['a', 'b', 'c'], [1, 2]]) + MultiIndex([('a', 1), + ('a', 2), + ('b', 1), + ('b', 2), + ('c', 1), + ('c', 2)], + names=['foo', 'bar']) + >>> idx.set_levels(['a', 'b', 'c'], level=0) + MultiIndex([('a', 'one'), + ('a', 'two'), + ('b', 'one'), + ('b', 'two'), + ('c', 'one'), + ('c', 'two')], + names=['foo', 'bar']) + >>> idx.set_levels(['a', 'b'], level='bar') + MultiIndex([(1, 'a'), + (1, 'b'), + (2, 'a'), + (2, 'b'), + (3, 'a'), + (3, 'b')], + names=['foo', 'bar']) + + If any of the levels passed to ``set_levels()`` exceeds the + existing length, all of the values from that argument will + be stored in the MultiIndex levels, though the values will + be truncated in the MultiIndex output. + + >>> idx.set_levels([['a', 'b', 'c'], [1, 2, 3, 4]], level=[0, 1]) + MultiIndex([('a', 1), + ('a', 2), + ('b', 1), + ('b', 2), + ('c', 1), + ('c', 2)], + names=['foo', 'bar']) + >>> idx.set_levels([['a', 'b', 'c'], [1, 2, 3, 4]], level=[0, 1]).levels + FrozenList([['a', 'b', 'c'], [1, 2, 3, 4]]) + """ + + if isinstance(levels, Index): + pass + elif is_array_like(levels): + levels = Index(levels) + elif is_list_like(levels): + levels = list(levels) + + level, levels = _require_listlike(level, levels, "Levels") + idx = self._view() + idx._reset_identity() + idx._set_levels( + levels, level=level, validate=True, verify_integrity=verify_integrity + ) + return idx + + @property + def nlevels(self) -> int: + """ + Integer number of levels in this MultiIndex. + + Examples + -------- + >>> mi = pd.MultiIndex.from_arrays([['a'], ['b'], ['c']]) + >>> mi + MultiIndex([('a', 'b', 'c')], + ) + >>> mi.nlevels + 3 + """ + return len(self._levels) + + @property + def levshape(self) -> Shape: + """ + A tuple with the length of each level. + + Examples + -------- + >>> mi = pd.MultiIndex.from_arrays([['a'], ['b'], ['c']]) + >>> mi + MultiIndex([('a', 'b', 'c')], + ) + >>> mi.levshape + (1, 1, 1) + """ + return tuple(len(x) for x in self.levels) + + # -------------------------------------------------------------------- + # Codes Methods + + @property + def codes(self) -> FrozenList: + return self._codes + + def _set_codes( + self, + codes, + *, + level=None, + copy: bool = False, + validate: bool = True, + verify_integrity: bool = False, + ) -> None: + if validate: + if level is None and len(codes) != self.nlevels: + raise ValueError("Length of codes must match number of levels") + if level is not None and len(codes) != len(level): + raise ValueError("Length of codes must match length of levels.") + + level_numbers: list[int] | range + if level is None: + new_codes = FrozenList( + _coerce_indexer_frozen(level_codes, lev, copy=copy).view() + for lev, level_codes in zip(self._levels, codes) + ) + level_numbers = range(len(new_codes)) + else: + level_numbers = [self._get_level_number(lev) for lev in level] + new_codes_list = list(self._codes) + for lev_num, level_codes in zip(level_numbers, codes): + lev = self.levels[lev_num] + new_codes_list[lev_num] = _coerce_indexer_frozen( + level_codes, lev, copy=copy + ) + new_codes = FrozenList(new_codes_list) + + if verify_integrity: + new_codes = self._verify_integrity( + codes=new_codes, levels_to_verify=level_numbers + ) + + self._codes = new_codes + + self._reset_cache() + + def set_codes( + self, codes, *, level=None, verify_integrity: bool = True + ) -> MultiIndex: + """ + Set new codes on MultiIndex. Defaults to returning new index. + + Parameters + ---------- + codes : sequence or list of sequence + New codes to apply. + level : int, level name, or sequence of int/level names (default None) + Level(s) to set (None for all levels). + verify_integrity : bool, default True + If True, checks that levels and codes are compatible. + + Returns + ------- + new index (of same type and class...etc) or None + The same type as the caller or None if ``inplace=True``. + + Examples + -------- + >>> idx = pd.MultiIndex.from_tuples( + ... [(1, "one"), (1, "two"), (2, "one"), (2, "two")], names=["foo", "bar"] + ... ) + >>> idx + MultiIndex([(1, 'one'), + (1, 'two'), + (2, 'one'), + (2, 'two')], + names=['foo', 'bar']) + + >>> idx.set_codes([[1, 0, 1, 0], [0, 0, 1, 1]]) + MultiIndex([(2, 'one'), + (1, 'one'), + (2, 'two'), + (1, 'two')], + names=['foo', 'bar']) + >>> idx.set_codes([1, 0, 1, 0], level=0) + MultiIndex([(2, 'one'), + (1, 'two'), + (2, 'one'), + (1, 'two')], + names=['foo', 'bar']) + >>> idx.set_codes([0, 0, 1, 1], level='bar') + MultiIndex([(1, 'one'), + (1, 'one'), + (2, 'two'), + (2, 'two')], + names=['foo', 'bar']) + >>> idx.set_codes([[1, 0, 1, 0], [0, 0, 1, 1]], level=[0, 1]) + MultiIndex([(2, 'one'), + (1, 'one'), + (2, 'two'), + (1, 'two')], + names=['foo', 'bar']) + """ + + level, codes = _require_listlike(level, codes, "Codes") + idx = self._view() + idx._reset_identity() + idx._set_codes(codes, level=level, verify_integrity=verify_integrity) + return idx + + # -------------------------------------------------------------------- + # Index Internals + + @cache_readonly + def _engine(self): + # Calculate the number of bits needed to represent labels in each + # level, as log2 of their sizes: + # NaN values are shifted to 1 and missing values in other while + # calculating the indexer are shifted to 0 + sizes = np.ceil( + np.log2( + [len(level) + libindex.multiindex_nulls_shift for level in self.levels] + ) + ) + + # Sum bit counts, starting from the _right_.... + lev_bits = np.cumsum(sizes[::-1])[::-1] + + # ... in order to obtain offsets such that sorting the combination of + # shifted codes (one for each level, resulting in a unique integer) is + # equivalent to sorting lexicographically the codes themselves. Notice + # that each level needs to be shifted by the number of bits needed to + # represent the _previous_ ones: + offsets = np.concatenate([lev_bits[1:], [0]]).astype("uint64") + + # Check the total number of bits needed for our representation: + if lev_bits[0] > 64: + # The levels would overflow a 64 bit uint - use Python integers: + return MultiIndexPyIntEngine(self.levels, self.codes, offsets) + return MultiIndexUIntEngine(self.levels, self.codes, offsets) + + # Return type "Callable[..., MultiIndex]" of "_constructor" incompatible with return + # type "Type[MultiIndex]" in supertype "Index" + @property + def _constructor(self) -> Callable[..., MultiIndex]: # type: ignore[override] + return type(self).from_tuples + + @doc(Index._shallow_copy) + def _shallow_copy(self, values: np.ndarray, name=lib.no_default) -> MultiIndex: + names = name if name is not lib.no_default else self.names + + return type(self).from_tuples(values, sortorder=None, names=names) + + def _view(self) -> MultiIndex: + result = type(self)( + levels=self.levels, + codes=self.codes, + sortorder=self.sortorder, + names=self.names, + verify_integrity=False, + ) + result._cache = self._cache.copy() + result._cache.pop("levels", None) # GH32669 + return result + + # -------------------------------------------------------------------- + + # error: Signature of "copy" incompatible with supertype "Index" + def copy( # type: ignore[override] + self, + names=None, + deep: bool = False, + name=None, + ) -> Self: + """ + Make a copy of this object. + + Names, dtype, levels and codes can be passed and will be set on new copy. + + Parameters + ---------- + names : sequence, optional + deep : bool, default False + name : Label + Kept for compatibility with 1-dimensional Index. Should not be used. + + Returns + ------- + MultiIndex + + Notes + ----- + In most cases, there should be no functional difference from using + ``deep``, but if ``deep`` is passed it will attempt to deepcopy. + This could be potentially expensive on large MultiIndex objects. + + Examples + -------- + >>> mi = pd.MultiIndex.from_arrays([['a'], ['b'], ['c']]) + >>> mi + MultiIndex([('a', 'b', 'c')], + ) + >>> mi.copy() + MultiIndex([('a', 'b', 'c')], + ) + """ + names = self._validate_names(name=name, names=names, deep=deep) + keep_id = not deep + levels, codes = None, None + + if deep: + from copy import deepcopy + + levels = deepcopy(self.levels) + codes = deepcopy(self.codes) + + levels = levels if levels is not None else self.levels + codes = codes if codes is not None else self.codes + + new_index = type(self)( + levels=levels, + codes=codes, + sortorder=self.sortorder, + names=names, + verify_integrity=False, + ) + new_index._cache = self._cache.copy() + new_index._cache.pop("levels", None) # GH32669 + if keep_id: + new_index._id = self._id + return new_index + + def __array__(self, dtype=None, copy=None) -> np.ndarray: + """the array interface, return my values""" + return self.values + + def view(self, cls=None) -> Self: + """this is defined as a copy with the same identity""" + result = self.copy() + result._id = self._id + return result + + @doc(Index.__contains__) + def __contains__(self, key: Any) -> bool: + hash(key) + try: + self.get_loc(key) + return True + except (LookupError, TypeError, ValueError): + return False + + @cache_readonly + def dtype(self) -> np.dtype: + return np.dtype("O") + + def _is_memory_usage_qualified(self) -> bool: + """return a boolean if we need a qualified .info display""" + + def f(level) -> bool: + return "mixed" in level or "string" in level or "unicode" in level + + return any(f(level) for level in self._inferred_type_levels) + + # Cannot determine type of "memory_usage" + @doc(Index.memory_usage) # type: ignore[has-type] + def memory_usage(self, deep: bool = False) -> int: + # we are overwriting our base class to avoid + # computing .values here which could materialize + # a tuple representation unnecessarily + return self._nbytes(deep) + + @cache_readonly + def nbytes(self) -> int: + """return the number of bytes in the underlying data""" + return self._nbytes(False) + + def _nbytes(self, deep: bool = False) -> int: + """ + return the number of bytes in the underlying data + deeply introspect the level data if deep=True + + include the engine hashtable + + *this is in internal routine* + + """ + # for implementations with no useful getsizeof (PyPy) + objsize = 24 + + level_nbytes = sum(i.memory_usage(deep=deep) for i in self.levels) + label_nbytes = sum(i.nbytes for i in self.codes) + names_nbytes = sum(getsizeof(i, objsize) for i in self.names) + result = level_nbytes + label_nbytes + names_nbytes + + # include our engine hashtable + result += self._engine.sizeof(deep=deep) + return result + + # -------------------------------------------------------------------- + # Rendering Methods + + def _formatter_func(self, tup): + """ + Formats each item in tup according to its level's formatter function. + """ + formatter_funcs = [level._formatter_func for level in self.levels] + return tuple(func(val) for func, val in zip(formatter_funcs, tup)) + + def _get_values_for_csv( + self, *, na_rep: str = "nan", **kwargs + ) -> npt.NDArray[np.object_]: + new_levels = [] + new_codes = [] + + # go through the levels and format them + for level, level_codes in zip(self.levels, self.codes): + level_strs = level._get_values_for_csv(na_rep=na_rep, **kwargs) + # add nan values, if there are any + mask = level_codes == -1 + if mask.any(): + nan_index = len(level_strs) + # numpy 1.21 deprecated implicit string casting + level_strs = level_strs.astype(str) + level_strs = np.append(level_strs, na_rep) + assert not level_codes.flags.writeable # i.e. copy is needed + level_codes = level_codes.copy() # make writeable + level_codes[mask] = nan_index + new_levels.append(level_strs) + new_codes.append(level_codes) + + if len(new_levels) == 1: + # a single-level multi-index + return Index(new_levels[0].take(new_codes[0]))._get_values_for_csv() + else: + # reconstruct the multi-index + mi = MultiIndex( + levels=new_levels, + codes=new_codes, + names=self.names, + sortorder=self.sortorder, + verify_integrity=False, + ) + return mi._values + + def format( + self, + name: bool | None = None, + formatter: Callable | None = None, + na_rep: str | None = None, + names: bool = False, + space: int = 2, + sparsify=None, + adjoin: bool = True, + ) -> list: + warnings.warn( + # GH#55413 + f"{type(self).__name__}.format is deprecated and will be removed " + "in a future version. Convert using index.astype(str) or " + "index.map(formatter) instead.", + FutureWarning, + stacklevel=find_stack_level(), + ) + + if name is not None: + names = name + + if len(self) == 0: + return [] + + stringified_levels = [] + for lev, level_codes in zip(self.levels, self.codes): + na = na_rep if na_rep is not None else _get_na_rep(lev.dtype) + + if len(lev) > 0: + formatted = lev.take(level_codes).format(formatter=formatter) + + # we have some NA + mask = level_codes == -1 + if mask.any(): + formatted = np.array(formatted, dtype=object) + formatted[mask] = na + formatted = formatted.tolist() + + else: + # weird all NA case + formatted = [ + pprint_thing(na if isna(x) else x, escape_chars=("\t", "\r", "\n")) + for x in algos.take_nd(lev._values, level_codes) + ] + stringified_levels.append(formatted) + + result_levels = [] + for lev, lev_name in zip(stringified_levels, self.names): + level = [] + + if names: + level.append( + pprint_thing(lev_name, escape_chars=("\t", "\r", "\n")) + if lev_name is not None + else "" + ) + + level.extend(np.array(lev, dtype=object)) + result_levels.append(level) + + if sparsify is None: + sparsify = get_option("display.multi_sparse") + + if sparsify: + sentinel: Literal[""] | bool | lib.NoDefault = "" + # GH3547 use value of sparsify as sentinel if it's "Falsey" + assert isinstance(sparsify, bool) or sparsify is lib.no_default + if sparsify in [False, lib.no_default]: + sentinel = sparsify + # little bit of a kludge job for #1217 + result_levels = sparsify_labels( + result_levels, start=int(names), sentinel=sentinel + ) + + if adjoin: + adj = get_adjustment() + return adj.adjoin(space, *result_levels).split("\n") + else: + return result_levels + + def _format_multi( + self, + *, + include_names: bool, + sparsify: bool | None | lib.NoDefault, + formatter: Callable | None = None, + ) -> list: + if len(self) == 0: + return [] + + stringified_levels = [] + for lev, level_codes in zip(self.levels, self.codes): + na = _get_na_rep(lev.dtype) + + if len(lev) > 0: + taken = formatted = lev.take(level_codes) + formatted = taken._format_flat(include_name=False, formatter=formatter) + + # we have some NA + mask = level_codes == -1 + if mask.any(): + formatted = np.array(formatted, dtype=object) + formatted[mask] = na + formatted = formatted.tolist() + + else: + # weird all NA case + formatted = [ + pprint_thing(na if isna(x) else x, escape_chars=("\t", "\r", "\n")) + for x in algos.take_nd(lev._values, level_codes) + ] + stringified_levels.append(formatted) + + result_levels = [] + for lev, lev_name in zip(stringified_levels, self.names): + level = [] + + if include_names: + level.append( + pprint_thing(lev_name, escape_chars=("\t", "\r", "\n")) + if lev_name is not None + else "" + ) + + level.extend(np.array(lev, dtype=object)) + result_levels.append(level) + + if sparsify is None: + sparsify = get_option("display.multi_sparse") + + if sparsify: + sentinel: Literal[""] | bool | lib.NoDefault = "" + # GH3547 use value of sparsify as sentinel if it's "Falsey" + assert isinstance(sparsify, bool) or sparsify is lib.no_default + if sparsify is lib.no_default: + sentinel = sparsify + # little bit of a kludge job for #1217 + result_levels = sparsify_labels( + result_levels, start=int(include_names), sentinel=sentinel + ) + + return result_levels + + # -------------------------------------------------------------------- + # Names Methods + + def _get_names(self) -> FrozenList: + return FrozenList(self._names) + + def _set_names(self, names, *, level=None, validate: bool = True): + """ + Set new names on index. Each name has to be a hashable type. + + Parameters + ---------- + values : str or sequence + name(s) to set + level : int, level name, or sequence of int/level names (default None) + If the index is a MultiIndex (hierarchical), level(s) to set (None + for all levels). Otherwise level must be None + validate : bool, default True + validate that the names match level lengths + + Raises + ------ + TypeError if each name is not hashable. + + Notes + ----- + sets names on levels. WARNING: mutates! + + Note that you generally want to set this *after* changing levels, so + that it only acts on copies + """ + # GH 15110 + # Don't allow a single string for names in a MultiIndex + if names is not None and not is_list_like(names): + raise ValueError("Names should be list-like for a MultiIndex") + names = list(names) + + if validate: + if level is not None and len(names) != len(level): + raise ValueError("Length of names must match length of level.") + if level is None and len(names) != self.nlevels: + raise ValueError( + "Length of names must match number of levels in MultiIndex." + ) + + if level is None: + level = range(self.nlevels) + else: + level = [self._get_level_number(lev) for lev in level] + + # set the name + for lev, name in zip(level, names): + if name is not None: + # GH 20527 + # All items in 'names' need to be hashable: + if not is_hashable(name): + raise TypeError( + f"{type(self).__name__}.name must be a hashable type" + ) + self._names[lev] = name + + # If .levels has been accessed, the names in our cache will be stale. + self._reset_cache() + + names = property( + fset=_set_names, + fget=_get_names, + doc=""" + Names of levels in MultiIndex. + + Examples + -------- + >>> mi = pd.MultiIndex.from_arrays( + ... [[1, 2], [3, 4], [5, 6]], names=['x', 'y', 'z']) + >>> mi + MultiIndex([(1, 3, 5), + (2, 4, 6)], + names=['x', 'y', 'z']) + >>> mi.names + FrozenList(['x', 'y', 'z']) + """, + ) + + # -------------------------------------------------------------------- + + @cache_readonly + def inferred_type(self) -> str: + return "mixed" + + def _get_level_number(self, level) -> int: + count = self.names.count(level) + if (count > 1) and not is_integer(level): + raise ValueError( + f"The name {level} occurs multiple times, use a level number" + ) + try: + level = self.names.index(level) + except ValueError as err: + if not is_integer(level): + raise KeyError(f"Level {level} not found") from err + if level < 0: + level += self.nlevels + if level < 0: + orig_level = level - self.nlevels + raise IndexError( + f"Too many levels: Index has only {self.nlevels} levels, " + f"{orig_level} is not a valid level number" + ) from err + # Note: levels are zero-based + elif level >= self.nlevels: + raise IndexError( + f"Too many levels: Index has only {self.nlevels} levels, " + f"not {level + 1}" + ) from err + return level + + @cache_readonly + def is_monotonic_increasing(self) -> bool: + """ + Return a boolean if the values are equal or increasing. + """ + if any(-1 in code for code in self.codes): + return False + + if all(level.is_monotonic_increasing for level in self.levels): + # If each level is sorted, we can operate on the codes directly. GH27495 + return libalgos.is_lexsorted( + [x.astype("int64", copy=False) for x in self.codes] + ) + + # reversed() because lexsort() wants the most significant key last. + values = [ + self._get_level_values(i)._values for i in reversed(range(len(self.levels))) + ] + try: + # error: Argument 1 to "lexsort" has incompatible type + # "List[Union[ExtensionArray, ndarray[Any, Any]]]"; + # expected "Union[_SupportsArray[dtype[Any]], + # _NestedSequence[_SupportsArray[dtype[Any]]], bool, + # int, float, complex, str, bytes, _NestedSequence[Union + # [bool, int, float, complex, str, bytes]]]" + sort_order = np.lexsort(values) # type: ignore[arg-type] + return Index(sort_order).is_monotonic_increasing + except TypeError: + # we have mixed types and np.lexsort is not happy + return Index(self._values).is_monotonic_increasing + + @cache_readonly + def is_monotonic_decreasing(self) -> bool: + """ + Return a boolean if the values are equal or decreasing. + """ + # monotonic decreasing if and only if reverse is monotonic increasing + return self[::-1].is_monotonic_increasing + + @cache_readonly + def _inferred_type_levels(self) -> list[str]: + """return a list of the inferred types, one for each level""" + return [i.inferred_type for i in self.levels] + + @doc(Index.duplicated) + def duplicated(self, keep: DropKeep = "first") -> npt.NDArray[np.bool_]: + shape = tuple(len(lev) for lev in self.levels) + ids = get_group_index(self.codes, shape, sort=False, xnull=False) + + return duplicated(ids, keep) + + # error: Cannot override final attribute "_duplicated" + # (previously declared in base class "IndexOpsMixin") + _duplicated = duplicated # type: ignore[misc] + + def fillna(self, value=None, downcast=None): + """ + fillna is not implemented for MultiIndex + """ + raise NotImplementedError("isna is not defined for MultiIndex") + + @doc(Index.dropna) + def dropna(self, how: AnyAll = "any") -> MultiIndex: + nans = [level_codes == -1 for level_codes in self.codes] + if how == "any": + indexer = np.any(nans, axis=0) + elif how == "all": + indexer = np.all(nans, axis=0) + else: + raise ValueError(f"invalid how option: {how}") + + new_codes = [level_codes[~indexer] for level_codes in self.codes] + return self.set_codes(codes=new_codes) + + def _get_level_values(self, level: int, unique: bool = False) -> Index: + """ + Return vector of label values for requested level, + equal to the length of the index + + **this is an internal method** + + Parameters + ---------- + level : int + unique : bool, default False + if True, drop duplicated values + + Returns + ------- + Index + """ + lev = self.levels[level] + level_codes = self.codes[level] + name = self._names[level] + if unique: + level_codes = algos.unique(level_codes) + filled = algos.take_nd(lev._values, level_codes, fill_value=lev._na_value) + return lev._shallow_copy(filled, name=name) + + # error: Signature of "get_level_values" incompatible with supertype "Index" + def get_level_values(self, level) -> Index: # type: ignore[override] + """ + Return vector of label values for requested level. + + Length of returned vector is equal to the length of the index. + + Parameters + ---------- + level : int or str + ``level`` is either the integer position of the level in the + MultiIndex, or the name of the level. + + Returns + ------- + Index + Values is a level of this MultiIndex converted to + a single :class:`Index` (or subclass thereof). + + Notes + ----- + If the level contains missing values, the result may be casted to + ``float`` with missing values specified as ``NaN``. This is because + the level is converted to a regular ``Index``. + + Examples + -------- + Create a MultiIndex: + + >>> mi = pd.MultiIndex.from_arrays((list('abc'), list('def'))) + >>> mi.names = ['level_1', 'level_2'] + + Get level values by supplying level as either integer or name: + + >>> mi.get_level_values(0) + Index(['a', 'b', 'c'], dtype='object', name='level_1') + >>> mi.get_level_values('level_2') + Index(['d', 'e', 'f'], dtype='object', name='level_2') + + If a level contains missing values, the return type of the level + may be cast to ``float``. + + >>> pd.MultiIndex.from_arrays([[1, None, 2], [3, 4, 5]]).dtypes + level_0 int64 + level_1 int64 + dtype: object + >>> pd.MultiIndex.from_arrays([[1, None, 2], [3, 4, 5]]).get_level_values(0) + Index([1.0, nan, 2.0], dtype='float64') + """ + level = self._get_level_number(level) + values = self._get_level_values(level) + return values + + @doc(Index.unique) + def unique(self, level=None): + if level is None: + return self.drop_duplicates() + else: + level = self._get_level_number(level) + return self._get_level_values(level=level, unique=True) + + def to_frame( + self, + index: bool = True, + name=lib.no_default, + allow_duplicates: bool = False, + ) -> DataFrame: + """ + Create a DataFrame with the levels of the MultiIndex as columns. + + Column ordering is determined by the DataFrame constructor with data as + a dict. + + Parameters + ---------- + index : bool, default True + Set the index of the returned DataFrame as the original MultiIndex. + + name : list / sequence of str, optional + The passed names should substitute index level names. + + allow_duplicates : bool, optional default False + Allow duplicate column labels to be created. + + .. versionadded:: 1.5.0 + + Returns + ------- + DataFrame + + See Also + -------- + DataFrame : Two-dimensional, size-mutable, potentially heterogeneous + tabular data. + + Examples + -------- + >>> mi = pd.MultiIndex.from_arrays([['a', 'b'], ['c', 'd']]) + >>> mi + MultiIndex([('a', 'c'), + ('b', 'd')], + ) + + >>> df = mi.to_frame() + >>> df + 0 1 + a c a c + b d b d + + >>> df = mi.to_frame(index=False) + >>> df + 0 1 + 0 a c + 1 b d + + >>> df = mi.to_frame(name=['x', 'y']) + >>> df + x y + a c a c + b d b d + """ + from pandas import DataFrame + + if name is not lib.no_default: + if not is_list_like(name): + raise TypeError("'name' must be a list / sequence of column names.") + + if len(name) != len(self.levels): + raise ValueError( + "'name' should have same length as number of levels on index." + ) + idx_names = name + else: + idx_names = self._get_level_names() + + if not allow_duplicates and len(set(idx_names)) != len(idx_names): + raise ValueError( + "Cannot create duplicate column labels if allow_duplicates is False" + ) + + # Guarantee resulting column order - PY36+ dict maintains insertion order + result = DataFrame( + {level: self._get_level_values(level) for level in range(len(self.levels))}, + copy=False, + ) + result.columns = idx_names + + if index: + result.index = self + return result + + # error: Return type "Index" of "to_flat_index" incompatible with return type + # "MultiIndex" in supertype "Index" + def to_flat_index(self) -> Index: # type: ignore[override] + """ + Convert a MultiIndex to an Index of Tuples containing the level values. + + Returns + ------- + pd.Index + Index with the MultiIndex data represented in Tuples. + + See Also + -------- + MultiIndex.from_tuples : Convert flat index back to MultiIndex. + + Notes + ----- + This method will simply return the caller if called by anything other + than a MultiIndex. + + Examples + -------- + >>> index = pd.MultiIndex.from_product( + ... [['foo', 'bar'], ['baz', 'qux']], + ... names=['a', 'b']) + >>> index.to_flat_index() + Index([('foo', 'baz'), ('foo', 'qux'), + ('bar', 'baz'), ('bar', 'qux')], + dtype='object') + """ + return Index(self._values, tupleize_cols=False) + + def _is_lexsorted(self) -> bool: + """ + Return True if the codes are lexicographically sorted. + + Returns + ------- + bool + + Examples + -------- + In the below examples, the first level of the MultiIndex is sorted because + a>> pd.MultiIndex.from_arrays([['a', 'b', 'c'], + ... ['d', 'e', 'f']])._is_lexsorted() + True + >>> pd.MultiIndex.from_arrays([['a', 'b', 'c'], + ... ['d', 'f', 'e']])._is_lexsorted() + True + + In case there is a tie, the lexicographical sorting looks + at the next level of the MultiIndex. + + >>> pd.MultiIndex.from_arrays([[0, 1, 1], ['a', 'b', 'c']])._is_lexsorted() + True + >>> pd.MultiIndex.from_arrays([[0, 1, 1], ['a', 'c', 'b']])._is_lexsorted() + False + >>> pd.MultiIndex.from_arrays([['a', 'a', 'b', 'b'], + ... ['aa', 'bb', 'aa', 'bb']])._is_lexsorted() + True + >>> pd.MultiIndex.from_arrays([['a', 'a', 'b', 'b'], + ... ['bb', 'aa', 'aa', 'bb']])._is_lexsorted() + False + """ + return self._lexsort_depth == self.nlevels + + @cache_readonly + def _lexsort_depth(self) -> int: + """ + Compute and return the lexsort_depth, the number of levels of the + MultiIndex that are sorted lexically + + Returns + ------- + int + """ + if self.sortorder is not None: + return self.sortorder + return _lexsort_depth(self.codes, self.nlevels) + + def _sort_levels_monotonic(self, raise_if_incomparable: bool = False) -> MultiIndex: + """ + This is an *internal* function. + + Create a new MultiIndex from the current to monotonically sorted + items IN the levels. This does not actually make the entire MultiIndex + monotonic, JUST the levels. + + The resulting MultiIndex will have the same outward + appearance, meaning the same .values and ordering. It will also + be .equals() to the original. + + Returns + ------- + MultiIndex + + Examples + -------- + >>> mi = pd.MultiIndex(levels=[['a', 'b'], ['bb', 'aa']], + ... codes=[[0, 0, 1, 1], [0, 1, 0, 1]]) + >>> mi + MultiIndex([('a', 'bb'), + ('a', 'aa'), + ('b', 'bb'), + ('b', 'aa')], + ) + + >>> mi.sort_values() + MultiIndex([('a', 'aa'), + ('a', 'bb'), + ('b', 'aa'), + ('b', 'bb')], + ) + """ + if self._is_lexsorted() and self.is_monotonic_increasing: + return self + + new_levels = [] + new_codes = [] + + for lev, level_codes in zip(self.levels, self.codes): + if not lev.is_monotonic_increasing: + try: + # indexer to reorder the levels + indexer = lev.argsort() + except TypeError: + if raise_if_incomparable: + raise + else: + lev = lev.take(indexer) + + # indexer to reorder the level codes + indexer = ensure_platform_int(indexer) + ri = lib.get_reverse_indexer(indexer, len(indexer)) + level_codes = algos.take_nd(ri, level_codes, fill_value=-1) + + new_levels.append(lev) + new_codes.append(level_codes) + + return MultiIndex( + new_levels, + new_codes, + names=self.names, + sortorder=self.sortorder, + verify_integrity=False, + ) + + def remove_unused_levels(self) -> MultiIndex: + """ + Create new MultiIndex from current that removes unused levels. + + Unused level(s) means levels that are not expressed in the + labels. The resulting MultiIndex will have the same outward + appearance, meaning the same .values and ordering. It will + also be .equals() to the original. + + Returns + ------- + MultiIndex + + Examples + -------- + >>> mi = pd.MultiIndex.from_product([range(2), list('ab')]) + >>> mi + MultiIndex([(0, 'a'), + (0, 'b'), + (1, 'a'), + (1, 'b')], + ) + + >>> mi[2:] + MultiIndex([(1, 'a'), + (1, 'b')], + ) + + The 0 from the first level is not represented + and can be removed + + >>> mi2 = mi[2:].remove_unused_levels() + >>> mi2.levels + FrozenList([[1], ['a', 'b']]) + """ + new_levels = [] + new_codes = [] + + changed = False + for lev, level_codes in zip(self.levels, self.codes): + # Since few levels are typically unused, bincount() is more + # efficient than unique() - however it only accepts positive values + # (and drops order): + uniques = np.where(np.bincount(level_codes + 1) > 0)[0] - 1 + has_na = int(len(uniques) and (uniques[0] == -1)) + + if len(uniques) != len(lev) + has_na: + if lev.isna().any() and len(uniques) == len(lev): + break + # We have unused levels + changed = True + + # Recalculate uniques, now preserving order. + # Can easily be cythonized by exploiting the already existing + # "uniques" and stop parsing "level_codes" when all items + # are found: + uniques = algos.unique(level_codes) + if has_na: + na_idx = np.where(uniques == -1)[0] + # Just ensure that -1 is in first position: + uniques[[0, na_idx[0]]] = uniques[[na_idx[0], 0]] + + # codes get mapped from uniques to 0:len(uniques) + # -1 (if present) is mapped to last position + code_mapping = np.zeros(len(lev) + has_na) + # ... and reassigned value -1: + code_mapping[uniques] = np.arange(len(uniques)) - has_na + + level_codes = code_mapping[level_codes] + + # new levels are simple + lev = lev.take(uniques[has_na:]) + + new_levels.append(lev) + new_codes.append(level_codes) + + result = self.view() + + if changed: + result._reset_identity() + result._set_levels(new_levels, validate=False) + result._set_codes(new_codes, validate=False) + + return result + + # -------------------------------------------------------------------- + # Pickling Methods + + def __reduce__(self): + """Necessary for making this object picklable""" + d = { + "levels": list(self.levels), + "codes": list(self.codes), + "sortorder": self.sortorder, + "names": list(self.names), + } + return ibase._new_Index, (type(self), d), None + + # -------------------------------------------------------------------- + + def __getitem__(self, key): + if is_scalar(key): + key = com.cast_scalar_indexer(key) + + retval = [] + for lev, level_codes in zip(self.levels, self.codes): + if level_codes[key] == -1: + retval.append(np.nan) + else: + retval.append(lev[level_codes[key]]) + + return tuple(retval) + else: + # in general cannot be sure whether the result will be sorted + sortorder = None + if com.is_bool_indexer(key): + key = np.asarray(key, dtype=bool) + sortorder = self.sortorder + elif isinstance(key, slice): + if key.step is None or key.step > 0: + sortorder = self.sortorder + elif isinstance(key, Index): + key = np.asarray(key) + + new_codes = [level_codes[key] for level_codes in self.codes] + + return MultiIndex( + levels=self.levels, + codes=new_codes, + names=self.names, + sortorder=sortorder, + verify_integrity=False, + ) + + def _getitem_slice(self: MultiIndex, slobj: slice) -> MultiIndex: + """ + Fastpath for __getitem__ when we know we have a slice. + """ + sortorder = None + if slobj.step is None or slobj.step > 0: + sortorder = self.sortorder + + new_codes = [level_codes[slobj] for level_codes in self.codes] + + return type(self)( + levels=self.levels, + codes=new_codes, + names=self._names, + sortorder=sortorder, + verify_integrity=False, + ) + + @Appender(_index_shared_docs["take"] % _index_doc_kwargs) + def take( + self: MultiIndex, + indices, + axis: Axis = 0, + allow_fill: bool = True, + fill_value=None, + **kwargs, + ) -> MultiIndex: + nv.validate_take((), kwargs) + indices = ensure_platform_int(indices) + + # only fill if we are passing a non-None fill_value + allow_fill = self._maybe_disallow_fill(allow_fill, fill_value, indices) + + na_value = -1 + + taken = [lab.take(indices) for lab in self.codes] + if allow_fill: + mask = indices == -1 + if mask.any(): + masked = [] + for new_label in taken: + label_values = new_label + label_values[mask] = na_value + masked.append(np.asarray(label_values)) + taken = masked + + return MultiIndex( + levels=self.levels, codes=taken, names=self.names, verify_integrity=False + ) + + def append(self, other): + """ + Append a collection of Index options together. + + Parameters + ---------- + other : Index or list/tuple of indices + + Returns + ------- + Index + The combined index. + + Examples + -------- + >>> mi = pd.MultiIndex.from_arrays([['a'], ['b']]) + >>> mi + MultiIndex([('a', 'b')], + ) + >>> mi.append(mi) + MultiIndex([('a', 'b'), ('a', 'b')], + ) + """ + if not isinstance(other, (list, tuple)): + other = [other] + + if all( + (isinstance(o, MultiIndex) and o.nlevels >= self.nlevels) for o in other + ): + codes = [] + levels = [] + names = [] + for i in range(self.nlevels): + level_values = self.levels[i] + for mi in other: + level_values = level_values.union(mi.levels[i]) + level_codes = [ + recode_for_categories( + mi.codes[i], mi.levels[i], level_values, copy=False + ) + for mi in ([self, *other]) + ] + level_name = self.names[i] + if any(mi.names[i] != level_name for mi in other): + level_name = None + codes.append(np.concatenate(level_codes)) + levels.append(level_values) + names.append(level_name) + return MultiIndex( + codes=codes, levels=levels, names=names, verify_integrity=False + ) + + to_concat = (self._values,) + tuple(k._values for k in other) + new_tuples = np.concatenate(to_concat) + + # if all(isinstance(x, MultiIndex) for x in other): + try: + # We only get here if other contains at least one index with tuples, + # setting names to None automatically + return MultiIndex.from_tuples(new_tuples) + except (TypeError, IndexError): + return Index(new_tuples) + + def argsort( + self, *args, na_position: str = "last", **kwargs + ) -> npt.NDArray[np.intp]: + target = self._sort_levels_monotonic(raise_if_incomparable=True) + keys = [lev.codes for lev in target._get_codes_for_sorting()] + return lexsort_indexer(keys, na_position=na_position, codes_given=True) + + @Appender(_index_shared_docs["repeat"] % _index_doc_kwargs) + def repeat(self, repeats: int, axis=None) -> MultiIndex: + nv.validate_repeat((), {"axis": axis}) + # error: Incompatible types in assignment (expression has type "ndarray", + # variable has type "int") + repeats = ensure_platform_int(repeats) # type: ignore[assignment] + return MultiIndex( + levels=self.levels, + codes=[ + level_codes.view(np.ndarray).astype(np.intp, copy=False).repeat(repeats) + for level_codes in self.codes + ], + names=self.names, + sortorder=self.sortorder, + verify_integrity=False, + ) + + # error: Signature of "drop" incompatible with supertype "Index" + def drop( # type: ignore[override] + self, + codes, + level: Index | np.ndarray | Iterable[Hashable] | None = None, + errors: IgnoreRaise = "raise", + ) -> MultiIndex: + """ + Make a new :class:`pandas.MultiIndex` with the passed list of codes deleted. + + Parameters + ---------- + codes : array-like + Must be a list of tuples when ``level`` is not specified. + level : int or level name, default None + errors : str, default 'raise' + + Returns + ------- + MultiIndex + + Examples + -------- + >>> idx = pd.MultiIndex.from_product([(0, 1, 2), ('green', 'purple')], + ... names=["number", "color"]) + >>> idx + MultiIndex([(0, 'green'), + (0, 'purple'), + (1, 'green'), + (1, 'purple'), + (2, 'green'), + (2, 'purple')], + names=['number', 'color']) + >>> idx.drop([(1, 'green'), (2, 'purple')]) + MultiIndex([(0, 'green'), + (0, 'purple'), + (1, 'purple'), + (2, 'green')], + names=['number', 'color']) + + We can also drop from a specific level. + + >>> idx.drop('green', level='color') + MultiIndex([(0, 'purple'), + (1, 'purple'), + (2, 'purple')], + names=['number', 'color']) + + >>> idx.drop([1, 2], level=0) + MultiIndex([(0, 'green'), + (0, 'purple')], + names=['number', 'color']) + """ + if level is not None: + return self._drop_from_level(codes, level, errors) + + if not isinstance(codes, (np.ndarray, Index)): + try: + codes = com.index_labels_to_array(codes, dtype=np.dtype("object")) + except ValueError: + pass + + inds = [] + for level_codes in codes: + try: + loc = self.get_loc(level_codes) + # get_loc returns either an integer, a slice, or a boolean + # mask + if isinstance(loc, int): + inds.append(loc) + elif isinstance(loc, slice): + step = loc.step if loc.step is not None else 1 + inds.extend(range(loc.start, loc.stop, step)) + elif com.is_bool_indexer(loc): + if self._lexsort_depth == 0: + warnings.warn( + "dropping on a non-lexsorted multi-index " + "without a level parameter may impact performance.", + PerformanceWarning, + stacklevel=find_stack_level(), + ) + loc = loc.nonzero()[0] + inds.extend(loc) + else: + msg = f"unsupported indexer of type {type(loc)}" + raise AssertionError(msg) + except KeyError: + if errors != "ignore": + raise + + return self.delete(inds) + + def _drop_from_level( + self, codes, level, errors: IgnoreRaise = "raise" + ) -> MultiIndex: + codes = com.index_labels_to_array(codes) + i = self._get_level_number(level) + index = self.levels[i] + values = index.get_indexer(codes) + # If nan should be dropped it will equal -1 here. We have to check which values + # are not nan and equal -1, this means they are missing in the index + nan_codes = isna(codes) + values[(np.equal(nan_codes, False)) & (values == -1)] = -2 + if index.shape[0] == self.shape[0]: + values[np.equal(nan_codes, True)] = -2 + + not_found = codes[values == -2] + if len(not_found) != 0 and errors != "ignore": + raise KeyError(f"labels {not_found} not found in level") + mask = ~algos.isin(self.codes[i], values) + + return self[mask] + + def swaplevel(self, i=-2, j=-1) -> MultiIndex: + """ + Swap level i with level j. + + Calling this method does not change the ordering of the values. + + Parameters + ---------- + i : int, str, default -2 + First level of index to be swapped. Can pass level name as string. + Type of parameters can be mixed. + j : int, str, default -1 + Second level of index to be swapped. Can pass level name as string. + Type of parameters can be mixed. + + Returns + ------- + MultiIndex + A new MultiIndex. + + See Also + -------- + Series.swaplevel : Swap levels i and j in a MultiIndex. + DataFrame.swaplevel : Swap levels i and j in a MultiIndex on a + particular axis. + + Examples + -------- + >>> mi = pd.MultiIndex(levels=[['a', 'b'], ['bb', 'aa']], + ... codes=[[0, 0, 1, 1], [0, 1, 0, 1]]) + >>> mi + MultiIndex([('a', 'bb'), + ('a', 'aa'), + ('b', 'bb'), + ('b', 'aa')], + ) + >>> mi.swaplevel(0, 1) + MultiIndex([('bb', 'a'), + ('aa', 'a'), + ('bb', 'b'), + ('aa', 'b')], + ) + """ + new_levels = list(self.levels) + new_codes = list(self.codes) + new_names = list(self.names) + + i = self._get_level_number(i) + j = self._get_level_number(j) + + new_levels[i], new_levels[j] = new_levels[j], new_levels[i] + new_codes[i], new_codes[j] = new_codes[j], new_codes[i] + new_names[i], new_names[j] = new_names[j], new_names[i] + + return MultiIndex( + levels=new_levels, codes=new_codes, names=new_names, verify_integrity=False + ) + + def reorder_levels(self, order) -> MultiIndex: + """ + Rearrange levels using input order. May not drop or duplicate levels. + + Parameters + ---------- + order : list of int or list of str + List representing new level order. Reference level by number + (position) or by key (label). + + Returns + ------- + MultiIndex + + Examples + -------- + >>> mi = pd.MultiIndex.from_arrays([[1, 2], [3, 4]], names=['x', 'y']) + >>> mi + MultiIndex([(1, 3), + (2, 4)], + names=['x', 'y']) + + >>> mi.reorder_levels(order=[1, 0]) + MultiIndex([(3, 1), + (4, 2)], + names=['y', 'x']) + + >>> mi.reorder_levels(order=['y', 'x']) + MultiIndex([(3, 1), + (4, 2)], + names=['y', 'x']) + """ + order = [self._get_level_number(i) for i in order] + result = self._reorder_ilevels(order) + return result + + def _reorder_ilevels(self, order) -> MultiIndex: + if len(order) != self.nlevels: + raise AssertionError( + f"Length of order must be same as number of levels ({self.nlevels}), " + f"got {len(order)}" + ) + new_levels = [self.levels[i] for i in order] + new_codes = [self.codes[i] for i in order] + new_names = [self.names[i] for i in order] + + return MultiIndex( + levels=new_levels, codes=new_codes, names=new_names, verify_integrity=False + ) + + def _recode_for_new_levels( + self, new_levels, copy: bool = True + ) -> Generator[np.ndarray, None, None]: + if len(new_levels) > self.nlevels: + raise AssertionError( + f"Length of new_levels ({len(new_levels)}) " + f"must be <= self.nlevels ({self.nlevels})" + ) + for i in range(len(new_levels)): + yield recode_for_categories( + self.codes[i], self.levels[i], new_levels[i], copy=copy + ) + + def _get_codes_for_sorting(self) -> list[Categorical]: + """ + we are categorizing our codes by using the + available categories (all, not just observed) + excluding any missing ones (-1); this is in preparation + for sorting, where we need to disambiguate that -1 is not + a valid valid + """ + + def cats(level_codes): + return np.arange( + np.array(level_codes).max() + 1 if len(level_codes) else 0, + dtype=level_codes.dtype, + ) + + return [ + Categorical.from_codes(level_codes, cats(level_codes), True, validate=False) + for level_codes in self.codes + ] + + def sortlevel( + self, + level: IndexLabel = 0, + ascending: bool | list[bool] = True, + sort_remaining: bool = True, + na_position: str = "first", + ) -> tuple[MultiIndex, npt.NDArray[np.intp]]: + """ + Sort MultiIndex at the requested level. + + The result will respect the original ordering of the associated + factor at that level. + + Parameters + ---------- + level : list-like, int or str, default 0 + If a string is given, must be a name of the level. + If list-like must be names or ints of levels. + ascending : bool, default True + False to sort in descending order. + Can also be a list to specify a directed ordering. + sort_remaining : sort by the remaining levels after level + na_position : {'first' or 'last'}, default 'first' + Argument 'first' puts NaNs at the beginning, 'last' puts NaNs at + the end. + + .. versionadded:: 2.1.0 + + Returns + ------- + sorted_index : pd.MultiIndex + Resulting index. + indexer : np.ndarray[np.intp] + Indices of output values in original index. + + Examples + -------- + >>> mi = pd.MultiIndex.from_arrays([[0, 0], [2, 1]]) + >>> mi + MultiIndex([(0, 2), + (0, 1)], + ) + + >>> mi.sortlevel() + (MultiIndex([(0, 1), + (0, 2)], + ), array([1, 0])) + + >>> mi.sortlevel(sort_remaining=False) + (MultiIndex([(0, 2), + (0, 1)], + ), array([0, 1])) + + >>> mi.sortlevel(1) + (MultiIndex([(0, 1), + (0, 2)], + ), array([1, 0])) + + >>> mi.sortlevel(1, ascending=False) + (MultiIndex([(0, 2), + (0, 1)], + ), array([0, 1])) + """ + if not is_list_like(level): + level = [level] + # error: Item "Hashable" of "Union[Hashable, Sequence[Hashable]]" has + # no attribute "__iter__" (not iterable) + level = [ + self._get_level_number(lev) for lev in level # type: ignore[union-attr] + ] + sortorder = None + + codes = [self.codes[lev] for lev in level] + # we have a directed ordering via ascending + if isinstance(ascending, list): + if not len(level) == len(ascending): + raise ValueError("level must have same length as ascending") + elif sort_remaining: + codes.extend( + [self.codes[lev] for lev in range(len(self.levels)) if lev not in level] + ) + else: + sortorder = level[0] + + indexer = lexsort_indexer( + codes, orders=ascending, na_position=na_position, codes_given=True + ) + + indexer = ensure_platform_int(indexer) + new_codes = [level_codes.take(indexer) for level_codes in self.codes] + + new_index = MultiIndex( + codes=new_codes, + levels=self.levels, + names=self.names, + sortorder=sortorder, + verify_integrity=False, + ) + + return new_index, indexer + + def _wrap_reindex_result(self, target, indexer, preserve_names: bool): + if not isinstance(target, MultiIndex): + if indexer is None: + target = self + elif (indexer >= 0).all(): + target = self.take(indexer) + else: + try: + target = MultiIndex.from_tuples(target) + except TypeError: + # not all tuples, see test_constructor_dict_multiindex_reindex_flat + return target + + target = self._maybe_preserve_names(target, preserve_names) + return target + + def _maybe_preserve_names(self, target: Index, preserve_names: bool) -> Index: + if ( + preserve_names + and target.nlevels == self.nlevels + and target.names != self.names + ): + target = target.copy(deep=False) + target.names = self.names + return target + + # -------------------------------------------------------------------- + # Indexing Methods + + def _check_indexing_error(self, key) -> None: + if not is_hashable(key) or is_iterator(key): + # We allow tuples if they are hashable, whereas other Index + # subclasses require scalar. + # We have to explicitly exclude generators, as these are hashable. + raise InvalidIndexError(key) + + @cache_readonly + def _should_fallback_to_positional(self) -> bool: + """ + Should integer key(s) be treated as positional? + """ + # GH#33355 + return self.levels[0]._should_fallback_to_positional + + def _get_indexer_strict( + self, key, axis_name: str + ) -> tuple[Index, npt.NDArray[np.intp]]: + keyarr = key + if not isinstance(keyarr, Index): + keyarr = com.asarray_tuplesafe(keyarr) + + if len(keyarr) and not isinstance(keyarr[0], tuple): + indexer = self._get_indexer_level_0(keyarr) + + self._raise_if_missing(key, indexer, axis_name) + return self[indexer], indexer + + return super()._get_indexer_strict(key, axis_name) + + def _raise_if_missing(self, key, indexer, axis_name: str) -> None: + keyarr = key + if not isinstance(key, Index): + keyarr = com.asarray_tuplesafe(key) + + if len(keyarr) and not isinstance(keyarr[0], tuple): + # i.e. same condition for special case in MultiIndex._get_indexer_strict + + mask = indexer == -1 + if mask.any(): + check = self.levels[0].get_indexer(keyarr) + cmask = check == -1 + if cmask.any(): + raise KeyError(f"{keyarr[cmask]} not in index") + # We get here when levels still contain values which are not + # actually in Index anymore + raise KeyError(f"{keyarr} not in index") + else: + return super()._raise_if_missing(key, indexer, axis_name) + + def _get_indexer_level_0(self, target) -> npt.NDArray[np.intp]: + """ + Optimized equivalent to `self.get_level_values(0).get_indexer_for(target)`. + """ + lev = self.levels[0] + codes = self._codes[0] + cat = Categorical.from_codes(codes=codes, categories=lev, validate=False) + ci = Index(cat) + return ci.get_indexer_for(target) + + def get_slice_bound( + self, + label: Hashable | Sequence[Hashable], + side: Literal["left", "right"], + ) -> int: + """ + For an ordered MultiIndex, compute slice bound + that corresponds to given label. + + Returns leftmost (one-past-the-rightmost if `side=='right') position + of given label. + + Parameters + ---------- + label : object or tuple of objects + side : {'left', 'right'} + + Returns + ------- + int + Index of label. + + Notes + ----- + This method only works if level 0 index of the MultiIndex is lexsorted. + + Examples + -------- + >>> mi = pd.MultiIndex.from_arrays([list('abbc'), list('gefd')]) + + Get the locations from the leftmost 'b' in the first level + until the end of the multiindex: + + >>> mi.get_slice_bound('b', side="left") + 1 + + Like above, but if you get the locations from the rightmost + 'b' in the first level and 'f' in the second level: + + >>> mi.get_slice_bound(('b','f'), side="right") + 3 + + See Also + -------- + MultiIndex.get_loc : Get location for a label or a tuple of labels. + MultiIndex.get_locs : Get location for a label/slice/list/mask or a + sequence of such. + """ + if not isinstance(label, tuple): + label = (label,) + return self._partial_tup_index(label, side=side) + + # pylint: disable-next=useless-parent-delegation + def slice_locs(self, start=None, end=None, step=None) -> tuple[int, int]: + """ + For an ordered MultiIndex, compute the slice locations for input + labels. + + The input labels can be tuples representing partial levels, e.g. for a + MultiIndex with 3 levels, you can pass a single value (corresponding to + the first level), or a 1-, 2-, or 3-tuple. + + Parameters + ---------- + start : label or tuple, default None + If None, defaults to the beginning + end : label or tuple + If None, defaults to the end + step : int or None + Slice step + + Returns + ------- + (start, end) : (int, int) + + Notes + ----- + This method only works if the MultiIndex is properly lexsorted. So, + if only the first 2 levels of a 3-level MultiIndex are lexsorted, + you can only pass two levels to ``.slice_locs``. + + Examples + -------- + >>> mi = pd.MultiIndex.from_arrays([list('abbd'), list('deff')], + ... names=['A', 'B']) + + Get the slice locations from the beginning of 'b' in the first level + until the end of the multiindex: + + >>> mi.slice_locs(start='b') + (1, 4) + + Like above, but stop at the end of 'b' in the first level and 'f' in + the second level: + + >>> mi.slice_locs(start='b', end=('b', 'f')) + (1, 3) + + See Also + -------- + MultiIndex.get_loc : Get location for a label or a tuple of labels. + MultiIndex.get_locs : Get location for a label/slice/list/mask or a + sequence of such. + """ + # This function adds nothing to its parent implementation (the magic + # happens in get_slice_bound method), but it adds meaningful doc. + return super().slice_locs(start, end, step) + + def _partial_tup_index(self, tup: tuple, side: Literal["left", "right"] = "left"): + if len(tup) > self._lexsort_depth: + raise UnsortedIndexError( + f"Key length ({len(tup)}) was greater than MultiIndex lexsort depth " + f"({self._lexsort_depth})" + ) + + n = len(tup) + start, end = 0, len(self) + zipped = zip(tup, self.levels, self.codes) + for k, (lab, lev, level_codes) in enumerate(zipped): + section = level_codes[start:end] + + loc: npt.NDArray[np.intp] | np.intp | int + if lab not in lev and not isna(lab): + # short circuit + try: + loc = algos.searchsorted(lev, lab, side=side) + except TypeError as err: + # non-comparable e.g. test_slice_locs_with_type_mismatch + raise TypeError(f"Level type mismatch: {lab}") from err + if not is_integer(loc): + # non-comparable level, e.g. test_groupby_example + raise TypeError(f"Level type mismatch: {lab}") + if side == "right" and loc >= 0: + loc -= 1 + return start + algos.searchsorted(section, loc, side=side) + + idx = self._get_loc_single_level_index(lev, lab) + if isinstance(idx, slice) and k < n - 1: + # Get start and end value from slice, necessary when a non-integer + # interval is given as input GH#37707 + start = idx.start + end = idx.stop + elif k < n - 1: + # error: Incompatible types in assignment (expression has type + # "Union[ndarray[Any, dtype[signedinteger[Any]]] + end = start + algos.searchsorted( # type: ignore[assignment] + section, idx, side="right" + ) + # error: Incompatible types in assignment (expression has type + # "Union[ndarray[Any, dtype[signedinteger[Any]]] + start = start + algos.searchsorted( # type: ignore[assignment] + section, idx, side="left" + ) + elif isinstance(idx, slice): + idx = idx.start + return start + algos.searchsorted(section, idx, side=side) + else: + return start + algos.searchsorted(section, idx, side=side) + + def _get_loc_single_level_index(self, level_index: Index, key: Hashable) -> int: + """ + If key is NA value, location of index unify as -1. + + Parameters + ---------- + level_index: Index + key : label + + Returns + ------- + loc : int + If key is NA value, loc is -1 + Else, location of key in index. + + See Also + -------- + Index.get_loc : The get_loc method for (single-level) index. + """ + if is_scalar(key) and isna(key): + # TODO: need is_valid_na_for_dtype(key, level_index.dtype) + return -1 + else: + return level_index.get_loc(key) + + def get_loc(self, key): + """ + Get location for a label or a tuple of labels. + + The location is returned as an integer/slice or boolean + mask. + + Parameters + ---------- + key : label or tuple of labels (one for each level) + + Returns + ------- + int, slice object or boolean mask + If the key is past the lexsort depth, the return may be a + boolean mask array, otherwise it is always a slice or int. + + See Also + -------- + Index.get_loc : The get_loc method for (single-level) index. + MultiIndex.slice_locs : Get slice location given start label(s) and + end label(s). + MultiIndex.get_locs : Get location for a label/slice/list/mask or a + sequence of such. + + Notes + ----- + The key cannot be a slice, list of same-level labels, a boolean mask, + or a sequence of such. If you want to use those, use + :meth:`MultiIndex.get_locs` instead. + + Examples + -------- + >>> mi = pd.MultiIndex.from_arrays([list('abb'), list('def')]) + + >>> mi.get_loc('b') + slice(1, 3, None) + + >>> mi.get_loc(('b', 'e')) + 1 + """ + self._check_indexing_error(key) + + def _maybe_to_slice(loc): + """convert integer indexer to boolean mask or slice if possible""" + if not isinstance(loc, np.ndarray) or loc.dtype != np.intp: + return loc + + loc = lib.maybe_indices_to_slice(loc, len(self)) + if isinstance(loc, slice): + return loc + + mask = np.empty(len(self), dtype="bool") + mask.fill(False) + mask[loc] = True + return mask + + if not isinstance(key, tuple): + loc = self._get_level_indexer(key, level=0) + return _maybe_to_slice(loc) + + keylen = len(key) + if self.nlevels < keylen: + raise KeyError( + f"Key length ({keylen}) exceeds index depth ({self.nlevels})" + ) + + if keylen == self.nlevels and self.is_unique: + # TODO: what if we have an IntervalIndex level? + # i.e. do we need _index_as_unique on that level? + try: + return self._engine.get_loc(key) + except KeyError as err: + raise KeyError(key) from err + except TypeError: + # e.g. test_partial_slicing_with_multiindex partial string slicing + loc, _ = self.get_loc_level(key, list(range(self.nlevels))) + return loc + + # -- partial selection or non-unique index + # break the key into 2 parts based on the lexsort_depth of the index; + # the first part returns a continuous slice of the index; the 2nd part + # needs linear search within the slice + i = self._lexsort_depth + lead_key, follow_key = key[:i], key[i:] + + if not lead_key: + start = 0 + stop = len(self) + else: + try: + start, stop = self.slice_locs(lead_key, lead_key) + except TypeError as err: + # e.g. test_groupby_example key = ((0, 0, 1, 2), "new_col") + # when self has 5 integer levels + raise KeyError(key) from err + + if start == stop: + raise KeyError(key) + + if not follow_key: + return slice(start, stop) + + warnings.warn( + "indexing past lexsort depth may impact performance.", + PerformanceWarning, + stacklevel=find_stack_level(), + ) + + loc = np.arange(start, stop, dtype=np.intp) + + for i, k in enumerate(follow_key, len(lead_key)): + mask = self.codes[i][loc] == self._get_loc_single_level_index( + self.levels[i], k + ) + if not mask.all(): + loc = loc[mask] + if not len(loc): + raise KeyError(key) + + return _maybe_to_slice(loc) if len(loc) != stop - start else slice(start, stop) + + def get_loc_level(self, key, level: IndexLabel = 0, drop_level: bool = True): + """ + Get location and sliced index for requested label(s)/level(s). + + Parameters + ---------- + key : label or sequence of labels + level : int/level name or list thereof, optional + drop_level : bool, default True + If ``False``, the resulting index will not drop any level. + + Returns + ------- + tuple + A 2-tuple where the elements : + + Element 0: int, slice object or boolean array. + + Element 1: The resulting sliced multiindex/index. If the key + contains all levels, this will be ``None``. + + See Also + -------- + MultiIndex.get_loc : Get location for a label or a tuple of labels. + MultiIndex.get_locs : Get location for a label/slice/list/mask or a + sequence of such. + + Examples + -------- + >>> mi = pd.MultiIndex.from_arrays([list('abb'), list('def')], + ... names=['A', 'B']) + + >>> mi.get_loc_level('b') + (slice(1, 3, None), Index(['e', 'f'], dtype='object', name='B')) + + >>> mi.get_loc_level('e', level='B') + (array([False, True, False]), Index(['b'], dtype='object', name='A')) + + >>> mi.get_loc_level(['b', 'e']) + (1, None) + """ + if not isinstance(level, (list, tuple)): + level = self._get_level_number(level) + else: + level = [self._get_level_number(lev) for lev in level] + + loc, mi = self._get_loc_level(key, level=level) + if not drop_level: + if lib.is_integer(loc): + # Slice index must be an integer or None + mi = self[loc : loc + 1] + else: + mi = self[loc] + return loc, mi + + def _get_loc_level(self, key, level: int | list[int] = 0): + """ + get_loc_level but with `level` known to be positional, not name-based. + """ + + # different name to distinguish from maybe_droplevels + def maybe_mi_droplevels(indexer, levels): + """ + If level does not exist or all levels were dropped, the exception + has to be handled outside. + """ + new_index = self[indexer] + + for i in sorted(levels, reverse=True): + new_index = new_index._drop_level_numbers([i]) + + return new_index + + if isinstance(level, (tuple, list)): + if len(key) != len(level): + raise AssertionError( + "Key for location must have same length as number of levels" + ) + result = None + for lev, k in zip(level, key): + loc, new_index = self._get_loc_level(k, level=lev) + if isinstance(loc, slice): + mask = np.zeros(len(self), dtype=bool) + mask[loc] = True + loc = mask + result = loc if result is None else result & loc + + try: + # FIXME: we should be only dropping levels on which we are + # scalar-indexing + mi = maybe_mi_droplevels(result, level) + except ValueError: + # droplevel failed because we tried to drop all levels, + # i.e. len(level) == self.nlevels + mi = self[result] + + return result, mi + + # kludge for #1796 + if isinstance(key, list): + key = tuple(key) + + if isinstance(key, tuple) and level == 0: + try: + # Check if this tuple is a single key in our first level + if key in self.levels[0]: + indexer = self._get_level_indexer(key, level=level) + new_index = maybe_mi_droplevels(indexer, [0]) + return indexer, new_index + except (TypeError, InvalidIndexError): + pass + + if not any(isinstance(k, slice) for k in key): + if len(key) == self.nlevels and self.is_unique: + # Complete key in unique index -> standard get_loc + try: + return (self._engine.get_loc(key), None) + except KeyError as err: + raise KeyError(key) from err + except TypeError: + # e.g. partial string indexing + # test_partial_string_timestamp_multiindex + pass + + # partial selection + indexer = self.get_loc(key) + ilevels = [i for i in range(len(key)) if key[i] != slice(None, None)] + if len(ilevels) == self.nlevels: + if is_integer(indexer): + # we are dropping all levels + return indexer, None + + # TODO: in some cases we still need to drop some levels, + # e.g. test_multiindex_perf_warn + # test_partial_string_timestamp_multiindex + ilevels = [ + i + for i in range(len(key)) + if ( + not isinstance(key[i], str) + or not self.levels[i]._supports_partial_string_indexing + ) + and key[i] != slice(None, None) + ] + if len(ilevels) == self.nlevels: + # TODO: why? + ilevels = [] + return indexer, maybe_mi_droplevels(indexer, ilevels) + + else: + indexer = None + for i, k in enumerate(key): + if not isinstance(k, slice): + loc_level = self._get_level_indexer(k, level=i) + if isinstance(loc_level, slice): + if com.is_null_slice(loc_level) or com.is_full_slice( + loc_level, len(self) + ): + # everything + continue + + # e.g. test_xs_IndexSlice_argument_not_implemented + k_index = np.zeros(len(self), dtype=bool) + k_index[loc_level] = True + + else: + k_index = loc_level + + elif com.is_null_slice(k): + # taking everything, does not affect `indexer` below + continue + + else: + # FIXME: this message can be inaccurate, e.g. + # test_series_varied_multiindex_alignment + raise TypeError(f"Expected label or tuple of labels, got {key}") + + if indexer is None: + indexer = k_index + else: + indexer &= k_index + if indexer is None: + indexer = slice(None, None) + ilevels = [i for i in range(len(key)) if key[i] != slice(None, None)] + return indexer, maybe_mi_droplevels(indexer, ilevels) + else: + indexer = self._get_level_indexer(key, level=level) + if ( + isinstance(key, str) + and self.levels[level]._supports_partial_string_indexing + ): + # check to see if we did an exact lookup vs sliced + check = self.levels[level].get_loc(key) + if not is_integer(check): + # e.g. test_partial_string_timestamp_multiindex + return indexer, self[indexer] + + try: + result_index = maybe_mi_droplevels(indexer, [level]) + except ValueError: + result_index = self[indexer] + + return indexer, result_index + + def _get_level_indexer( + self, key, level: int = 0, indexer: npt.NDArray[np.bool_] | None = None + ): + # `level` kwarg is _always_ positional, never name + # return a boolean array or slice showing where the key is + # in the totality of values + # if the indexer is provided, then use this + + level_index = self.levels[level] + level_codes = self.codes[level] + + def convert_indexer(start, stop, step, indexer=indexer, codes=level_codes): + # Compute a bool indexer to identify the positions to take. + # If we have an existing indexer, we only need to examine the + # subset of positions where the existing indexer is True. + if indexer is not None: + # we only need to look at the subset of codes where the + # existing indexer equals True + codes = codes[indexer] + + if step is None or step == 1: + new_indexer = (codes >= start) & (codes < stop) + else: + r = np.arange(start, stop, step, dtype=codes.dtype) + new_indexer = algos.isin(codes, r) + + if indexer is None: + return new_indexer + + indexer = indexer.copy() + indexer[indexer] = new_indexer + return indexer + + if isinstance(key, slice): + # handle a slice, returning a slice if we can + # otherwise a boolean indexer + step = key.step + is_negative_step = step is not None and step < 0 + + try: + if key.start is not None: + start = level_index.get_loc(key.start) + elif is_negative_step: + start = len(level_index) - 1 + else: + start = 0 + + if key.stop is not None: + stop = level_index.get_loc(key.stop) + elif is_negative_step: + stop = 0 + elif isinstance(start, slice): + stop = len(level_index) + else: + stop = len(level_index) - 1 + except KeyError: + # we have a partial slice (like looking up a partial date + # string) + start = stop = level_index.slice_indexer(key.start, key.stop, key.step) + step = start.step + + if isinstance(start, slice) or isinstance(stop, slice): + # we have a slice for start and/or stop + # a partial date slicer on a DatetimeIndex generates a slice + # note that the stop ALREADY includes the stopped point (if + # it was a string sliced) + start = getattr(start, "start", start) + stop = getattr(stop, "stop", stop) + return convert_indexer(start, stop, step) + + elif level > 0 or self._lexsort_depth == 0 or step is not None: + # need to have like semantics here to right + # searching as when we are using a slice + # so adjust the stop by 1 (so we include stop) + stop = (stop - 1) if is_negative_step else (stop + 1) + return convert_indexer(start, stop, step) + else: + # sorted, so can return slice object -> view + i = algos.searchsorted(level_codes, start, side="left") + j = algos.searchsorted(level_codes, stop, side="right") + return slice(i, j, step) + + else: + idx = self._get_loc_single_level_index(level_index, key) + + if level > 0 or self._lexsort_depth == 0: + # Desired level is not sorted + if isinstance(idx, slice): + # test_get_loc_partial_timestamp_multiindex + locs = (level_codes >= idx.start) & (level_codes < idx.stop) + return locs + + locs = np.asarray(level_codes == idx, dtype=bool) + + if not locs.any(): + # The label is present in self.levels[level] but unused: + raise KeyError(key) + return locs + + if isinstance(idx, slice): + # e.g. test_partial_string_timestamp_multiindex + start = algos.searchsorted(level_codes, idx.start, side="left") + # NB: "left" here bc of slice semantics + end = algos.searchsorted(level_codes, idx.stop, side="left") + else: + start = algos.searchsorted(level_codes, idx, side="left") + end = algos.searchsorted(level_codes, idx, side="right") + + if start == end: + # The label is present in self.levels[level] but unused: + raise KeyError(key) + return slice(start, end) + + def get_locs(self, seq) -> npt.NDArray[np.intp]: + """ + Get location for a sequence of labels. + + Parameters + ---------- + seq : label, slice, list, mask or a sequence of such + You should use one of the above for each level. + If a level should not be used, set it to ``slice(None)``. + + Returns + ------- + numpy.ndarray + NumPy array of integers suitable for passing to iloc. + + See Also + -------- + MultiIndex.get_loc : Get location for a label or a tuple of labels. + MultiIndex.slice_locs : Get slice location given start label(s) and + end label(s). + + Examples + -------- + >>> mi = pd.MultiIndex.from_arrays([list('abb'), list('def')]) + + >>> mi.get_locs('b') # doctest: +SKIP + array([1, 2], dtype=int64) + + >>> mi.get_locs([slice(None), ['e', 'f']]) # doctest: +SKIP + array([1, 2], dtype=int64) + + >>> mi.get_locs([[True, False, True], slice('e', 'f')]) # doctest: +SKIP + array([2], dtype=int64) + """ + + # must be lexsorted to at least as many levels + true_slices = [i for (i, s) in enumerate(com.is_true_slices(seq)) if s] + if true_slices and true_slices[-1] >= self._lexsort_depth: + raise UnsortedIndexError( + "MultiIndex slicing requires the index to be lexsorted: slicing " + f"on levels {true_slices}, lexsort depth {self._lexsort_depth}" + ) + + if any(x is Ellipsis for x in seq): + raise NotImplementedError( + "MultiIndex does not support indexing with Ellipsis" + ) + + n = len(self) + + def _to_bool_indexer(indexer) -> npt.NDArray[np.bool_]: + if isinstance(indexer, slice): + new_indexer = np.zeros(n, dtype=np.bool_) + new_indexer[indexer] = True + return new_indexer + return indexer + + # a bool indexer for the positions we want to take + indexer: npt.NDArray[np.bool_] | None = None + + for i, k in enumerate(seq): + lvl_indexer: npt.NDArray[np.bool_] | slice | None = None + + if com.is_bool_indexer(k): + if len(k) != n: + raise ValueError( + "cannot index with a boolean indexer that " + "is not the same length as the index" + ) + lvl_indexer = np.asarray(k) + if indexer is None: + lvl_indexer = lvl_indexer.copy() + + elif is_list_like(k): + # a collection of labels to include from this level (these are or'd) + + # GH#27591 check if this is a single tuple key in the level + try: + lvl_indexer = self._get_level_indexer(k, level=i, indexer=indexer) + except (InvalidIndexError, TypeError, KeyError) as err: + # InvalidIndexError e.g. non-hashable, fall back to treating + # this as a sequence of labels + # KeyError it can be ambiguous if this is a label or sequence + # of labels + # github.com/pandas-dev/pandas/issues/39424#issuecomment-871626708 + for x in k: + if not is_hashable(x): + # e.g. slice + raise err + # GH 39424: Ignore not founds + # GH 42351: No longer ignore not founds & enforced in 2.0 + # TODO: how to handle IntervalIndex level? (no test cases) + item_indexer = self._get_level_indexer( + x, level=i, indexer=indexer + ) + if lvl_indexer is None: + lvl_indexer = _to_bool_indexer(item_indexer) + elif isinstance(item_indexer, slice): + lvl_indexer[item_indexer] = True # type: ignore[index] + else: + lvl_indexer |= item_indexer + + if lvl_indexer is None: + # no matches we are done + # test_loc_getitem_duplicates_multiindex_empty_indexer + return np.array([], dtype=np.intp) + + elif com.is_null_slice(k): + # empty slice + if indexer is None and i == len(seq) - 1: + return np.arange(n, dtype=np.intp) + continue + + else: + # a slice or a single label + lvl_indexer = self._get_level_indexer(k, level=i, indexer=indexer) + + # update indexer + lvl_indexer = _to_bool_indexer(lvl_indexer) + if indexer is None: + indexer = lvl_indexer + else: + indexer &= lvl_indexer + if not np.any(indexer) and np.any(lvl_indexer): + raise KeyError(seq) + + # empty indexer + if indexer is None: + return np.array([], dtype=np.intp) + + pos_indexer = indexer.nonzero()[0] + return self._reorder_indexer(seq, pos_indexer) + + # -------------------------------------------------------------------- + + def _reorder_indexer( + self, + seq: tuple[Scalar | Iterable | AnyArrayLike, ...], + indexer: npt.NDArray[np.intp], + ) -> npt.NDArray[np.intp]: + """ + Reorder an indexer of a MultiIndex (self) so that the labels are in the + same order as given in seq + + Parameters + ---------- + seq : label/slice/list/mask or a sequence of such + indexer: a position indexer of self + + Returns + ------- + indexer : a sorted position indexer of self ordered as seq + """ + + # check if sorting is necessary + need_sort = False + for i, k in enumerate(seq): + if com.is_null_slice(k) or com.is_bool_indexer(k) or is_scalar(k): + pass + elif is_list_like(k): + if len(k) <= 1: # type: ignore[arg-type] + pass + elif self._is_lexsorted(): + # If the index is lexsorted and the list_like label + # in seq are sorted then we do not need to sort + k_codes = self.levels[i].get_indexer(k) + k_codes = k_codes[k_codes >= 0] # Filter absent keys + # True if the given codes are not ordered + need_sort = (k_codes[:-1] > k_codes[1:]).any() + else: + need_sort = True + elif isinstance(k, slice): + if self._is_lexsorted(): + need_sort = k.step is not None and k.step < 0 + else: + need_sort = True + else: + need_sort = True + if need_sort: + break + if not need_sort: + return indexer + + n = len(self) + keys: tuple[np.ndarray, ...] = () + # For each level of the sequence in seq, map the level codes with the + # order they appears in a list-like sequence + # This mapping is then use to reorder the indexer + for i, k in enumerate(seq): + if is_scalar(k): + # GH#34603 we want to treat a scalar the same as an all equal list + k = [k] + if com.is_bool_indexer(k): + new_order = np.arange(n)[indexer] + elif is_list_like(k): + # Generate a map with all level codes as sorted initially + if not isinstance(k, (np.ndarray, ExtensionArray, Index, ABCSeries)): + k = sanitize_array(k, None) + k = algos.unique(k) + key_order_map = np.ones(len(self.levels[i]), dtype=np.uint64) * len( + self.levels[i] + ) + # Set order as given in the indexer list + level_indexer = self.levels[i].get_indexer(k) + level_indexer = level_indexer[level_indexer >= 0] # Filter absent keys + key_order_map[level_indexer] = np.arange(len(level_indexer)) + + new_order = key_order_map[self.codes[i][indexer]] + elif isinstance(k, slice) and k.step is not None and k.step < 0: + # flip order for negative step + new_order = np.arange(n)[::-1][indexer] + elif isinstance(k, slice) and k.start is None and k.stop is None: + # slice(None) should not determine order GH#31330 + new_order = np.ones((n,), dtype=np.intp)[indexer] + else: + # For all other case, use the same order as the level + new_order = np.arange(n)[indexer] + keys = (new_order,) + keys + + # Find the reordering using lexsort on the keys mapping + ind = np.lexsort(keys) + return indexer[ind] + + def truncate(self, before=None, after=None) -> MultiIndex: + """ + Slice index between two labels / tuples, return new MultiIndex. + + Parameters + ---------- + before : label or tuple, can be partial. Default None + None defaults to start. + after : label or tuple, can be partial. Default None + None defaults to end. + + Returns + ------- + MultiIndex + The truncated MultiIndex. + + Examples + -------- + >>> mi = pd.MultiIndex.from_arrays([['a', 'b', 'c'], ['x', 'y', 'z']]) + >>> mi + MultiIndex([('a', 'x'), ('b', 'y'), ('c', 'z')], + ) + >>> mi.truncate(before='a', after='b') + MultiIndex([('a', 'x'), ('b', 'y')], + ) + """ + if after and before and after < before: + raise ValueError("after < before") + + i, j = self.levels[0].slice_locs(before, after) + left, right = self.slice_locs(before, after) + + new_levels = list(self.levels) + new_levels[0] = new_levels[0][i:j] + + new_codes = [level_codes[left:right] for level_codes in self.codes] + new_codes[0] = new_codes[0] - i + + return MultiIndex( + levels=new_levels, + codes=new_codes, + names=self._names, + verify_integrity=False, + ) + + def equals(self, other: object) -> bool: + """ + Determines if two MultiIndex objects have the same labeling information + (the levels themselves do not necessarily have to be the same) + + See Also + -------- + equal_levels + """ + if self.is_(other): + return True + + if not isinstance(other, Index): + return False + + if len(self) != len(other): + return False + + if not isinstance(other, MultiIndex): + # d-level MultiIndex can equal d-tuple Index + if not self._should_compare(other): + # object Index or Categorical[object] may contain tuples + return False + return array_equivalent(self._values, other._values) + + if self.nlevels != other.nlevels: + return False + + for i in range(self.nlevels): + self_codes = self.codes[i] + other_codes = other.codes[i] + self_mask = self_codes == -1 + other_mask = other_codes == -1 + if not np.array_equal(self_mask, other_mask): + return False + self_codes = self_codes[~self_mask] + self_values = self.levels[i]._values.take(self_codes) + + other_codes = other_codes[~other_mask] + other_values = other.levels[i]._values.take(other_codes) + + # since we use NaT both datetime64 and timedelta64 we can have a + # situation where a level is typed say timedelta64 in self (IOW it + # has other values than NaT) but types datetime64 in other (where + # its all NaT) but these are equivalent + if len(self_values) == 0 and len(other_values) == 0: + continue + + if not isinstance(self_values, np.ndarray): + # i.e. ExtensionArray + if not self_values.equals(other_values): + return False + elif not isinstance(other_values, np.ndarray): + # i.e. other is ExtensionArray + if not other_values.equals(self_values): + return False + else: + if not array_equivalent(self_values, other_values): + return False + + return True + + def equal_levels(self, other: MultiIndex) -> bool: + """ + Return True if the levels of both MultiIndex objects are the same + + """ + if self.nlevels != other.nlevels: + return False + + for i in range(self.nlevels): + if not self.levels[i].equals(other.levels[i]): + return False + return True + + # -------------------------------------------------------------------- + # Set Methods + + def _union(self, other, sort) -> MultiIndex: + other, result_names = self._convert_can_do_setop(other) + if other.has_duplicates: + # This is only necessary if other has dupes, + # otherwise difference is faster + result = super()._union(other, sort) + + if isinstance(result, MultiIndex): + return result + return MultiIndex.from_arrays( + zip(*result), sortorder=None, names=result_names + ) + + else: + right_missing = other.difference(self, sort=False) + if len(right_missing): + result = self.append(right_missing) + else: + result = self._get_reconciled_name_object(other) + + if sort is not False: + try: + result = result.sort_values() + except TypeError: + if sort is True: + raise + warnings.warn( + "The values in the array are unorderable. " + "Pass `sort=False` to suppress this warning.", + RuntimeWarning, + stacklevel=find_stack_level(), + ) + return result + + def _is_comparable_dtype(self, dtype: DtypeObj) -> bool: + return is_object_dtype(dtype) + + def _get_reconciled_name_object(self, other) -> MultiIndex: + """ + If the result of a set operation will be self, + return self, unless the names change, in which + case make a shallow copy of self. + """ + names = self._maybe_match_names(other) + if self.names != names: + # error: Cannot determine type of "rename" + return self.rename(names) # type: ignore[has-type] + return self + + def _maybe_match_names(self, other): + """ + Try to find common names to attach to the result of an operation between + a and b. Return a consensus list of names if they match at least partly + or list of None if they have completely different names. + """ + if len(self.names) != len(other.names): + return [None] * len(self.names) + names = [] + for a_name, b_name in zip(self.names, other.names): + if a_name == b_name: + names.append(a_name) + else: + # TODO: what if they both have np.nan for their names? + names.append(None) + return names + + def _wrap_intersection_result(self, other, result) -> MultiIndex: + _, result_names = self._convert_can_do_setop(other) + return result.set_names(result_names) + + def _wrap_difference_result(self, other, result: MultiIndex) -> MultiIndex: + _, result_names = self._convert_can_do_setop(other) + + if len(result) == 0: + return result.remove_unused_levels().set_names(result_names) + else: + return result.set_names(result_names) + + def _convert_can_do_setop(self, other): + result_names = self.names + + if not isinstance(other, Index): + if len(other) == 0: + return self[:0], self.names + else: + msg = "other must be a MultiIndex or a list of tuples" + try: + other = MultiIndex.from_tuples(other, names=self.names) + except (ValueError, TypeError) as err: + # ValueError raised by tuples_to_object_array if we + # have non-object dtype + raise TypeError(msg) from err + else: + result_names = get_unanimous_names(self, other) + + return other, result_names + + # -------------------------------------------------------------------- + + @doc(Index.astype) + def astype(self, dtype, copy: bool = True): + dtype = pandas_dtype(dtype) + if isinstance(dtype, CategoricalDtype): + msg = "> 1 ndim Categorical are not supported at this time" + raise NotImplementedError(msg) + if not is_object_dtype(dtype): + raise TypeError( + "Setting a MultiIndex dtype to anything other than object " + "is not supported" + ) + if copy is True: + return self._view() + return self + + def _validate_fill_value(self, item): + if isinstance(item, MultiIndex): + # GH#43212 + if item.nlevels != self.nlevels: + raise ValueError("Item must have length equal to number of levels.") + return item._values + elif not isinstance(item, tuple): + # Pad the key with empty strings if lower levels of the key + # aren't specified: + item = (item,) + ("",) * (self.nlevels - 1) + elif len(item) != self.nlevels: + raise ValueError("Item must have length equal to number of levels.") + return item + + def putmask(self, mask, value: MultiIndex) -> MultiIndex: + """ + Return a new MultiIndex of the values set with the mask. + + Parameters + ---------- + mask : array like + value : MultiIndex + Must either be the same length as self or length one + + Returns + ------- + MultiIndex + """ + mask, noop = validate_putmask(self, mask) + if noop: + return self.copy() + + if len(mask) == len(value): + subset = value[mask].remove_unused_levels() + else: + subset = value.remove_unused_levels() + + new_levels = [] + new_codes = [] + + for i, (value_level, level, level_codes) in enumerate( + zip(subset.levels, self.levels, self.codes) + ): + new_level = level.union(value_level, sort=False) + value_codes = new_level.get_indexer_for(subset.get_level_values(i)) + new_code = ensure_int64(level_codes) + new_code[mask] = value_codes + new_levels.append(new_level) + new_codes.append(new_code) + + return MultiIndex( + levels=new_levels, codes=new_codes, names=self.names, verify_integrity=False + ) + + def insert(self, loc: int, item) -> MultiIndex: + """ + Make new MultiIndex inserting new item at location + + Parameters + ---------- + loc : int + item : tuple + Must be same length as number of levels in the MultiIndex + + Returns + ------- + new_index : Index + """ + item = self._validate_fill_value(item) + + new_levels = [] + new_codes = [] + for k, level, level_codes in zip(item, self.levels, self.codes): + if k not in level: + # have to insert into level + # must insert at end otherwise you have to recompute all the + # other codes + lev_loc = len(level) + level = level.insert(lev_loc, k) + else: + lev_loc = level.get_loc(k) + + new_levels.append(level) + new_codes.append(np.insert(ensure_int64(level_codes), loc, lev_loc)) + + return MultiIndex( + levels=new_levels, codes=new_codes, names=self.names, verify_integrity=False + ) + + def delete(self, loc) -> MultiIndex: + """ + Make new index with passed location deleted + + Returns + ------- + new_index : MultiIndex + """ + new_codes = [np.delete(level_codes, loc) for level_codes in self.codes] + return MultiIndex( + levels=self.levels, + codes=new_codes, + names=self.names, + verify_integrity=False, + ) + + @doc(Index.isin) + def isin(self, values, level=None) -> npt.NDArray[np.bool_]: + if isinstance(values, Generator): + values = list(values) + + if level is None: + if len(values) == 0: + return np.zeros((len(self),), dtype=np.bool_) + if not isinstance(values, MultiIndex): + values = MultiIndex.from_tuples(values) + return values.unique().get_indexer_for(self) != -1 + else: + num = self._get_level_number(level) + levs = self.get_level_values(num) + + if levs.size == 0: + return np.zeros(len(levs), dtype=np.bool_) + return levs.isin(values) + + # error: Incompatible types in assignment (expression has type overloaded function, + # base class "Index" defined the type as "Callable[[Index, Any, bool], Any]") + rename = Index.set_names # type: ignore[assignment] + + # --------------------------------------------------------------- + # Arithmetic/Numeric Methods - Disabled + + __add__ = make_invalid_op("__add__") + __radd__ = make_invalid_op("__radd__") + __iadd__ = make_invalid_op("__iadd__") + __sub__ = make_invalid_op("__sub__") + __rsub__ = make_invalid_op("__rsub__") + __isub__ = make_invalid_op("__isub__") + __pow__ = make_invalid_op("__pow__") + __rpow__ = make_invalid_op("__rpow__") + __mul__ = make_invalid_op("__mul__") + __rmul__ = make_invalid_op("__rmul__") + __floordiv__ = make_invalid_op("__floordiv__") + __rfloordiv__ = make_invalid_op("__rfloordiv__") + __truediv__ = make_invalid_op("__truediv__") + __rtruediv__ = make_invalid_op("__rtruediv__") + __mod__ = make_invalid_op("__mod__") + __rmod__ = make_invalid_op("__rmod__") + __divmod__ = make_invalid_op("__divmod__") + __rdivmod__ = make_invalid_op("__rdivmod__") + # Unary methods disabled + __neg__ = make_invalid_op("__neg__") + __pos__ = make_invalid_op("__pos__") + __abs__ = make_invalid_op("__abs__") + __invert__ = make_invalid_op("__invert__") + + +def _lexsort_depth(codes: list[np.ndarray], nlevels: int) -> int: + """Count depth (up to a maximum of `nlevels`) with which codes are lexsorted.""" + int64_codes = [ensure_int64(level_codes) for level_codes in codes] + for k in range(nlevels, 0, -1): + if libalgos.is_lexsorted(int64_codes[:k]): + return k + return 0 + + +def sparsify_labels(label_list, start: int = 0, sentinel: object = ""): + pivoted = list(zip(*label_list)) + k = len(label_list) + + result = pivoted[: start + 1] + prev = pivoted[start] + + for cur in pivoted[start + 1 :]: + sparse_cur = [] + + for i, (p, t) in enumerate(zip(prev, cur)): + if i == k - 1: + sparse_cur.append(t) + # error: Argument 1 to "append" of "list" has incompatible + # type "list[Any]"; expected "tuple[Any, ...]" + result.append(sparse_cur) # type: ignore[arg-type] + break + + if p == t: + sparse_cur.append(sentinel) + else: + sparse_cur.extend(cur[i:]) + # error: Argument 1 to "append" of "list" has incompatible + # type "list[Any]"; expected "tuple[Any, ...]" + result.append(sparse_cur) # type: ignore[arg-type] + break + + prev = cur + + return list(zip(*result)) + + +def _get_na_rep(dtype: DtypeObj) -> str: + if isinstance(dtype, ExtensionDtype): + return f"{dtype.na_value}" + else: + dtype_type = dtype.type + + return {np.datetime64: "NaT", np.timedelta64: "NaT"}.get(dtype_type, "NaN") + + +def maybe_droplevels(index: Index, key) -> Index: + """ + Attempt to drop level or levels from the given index. + + Parameters + ---------- + index: Index + key : scalar or tuple + + Returns + ------- + Index + """ + # drop levels + original_index = index + if isinstance(key, tuple): + # Caller is responsible for ensuring the key is not an entry in the first + # level of the MultiIndex. + for _ in key: + try: + index = index._drop_level_numbers([0]) + except ValueError: + # we have dropped too much, so back out + return original_index + else: + try: + index = index._drop_level_numbers([0]) + except ValueError: + pass + + return index + + +def _coerce_indexer_frozen(array_like, categories, copy: bool = False) -> np.ndarray: + """ + Coerce the array-like indexer to the smallest integer dtype that can encode all + of the given categories. + + Parameters + ---------- + array_like : array-like + categories : array-like + copy : bool + + Returns + ------- + np.ndarray + Non-writeable. + """ + array_like = coerce_indexer_dtype(array_like, categories) + if copy: + array_like = array_like.copy() + array_like.flags.writeable = False + return array_like + + +def _require_listlike(level, arr, arrname: str): + """ + Ensure that level is either None or listlike, and arr is list-of-listlike. + """ + if level is not None and not is_list_like(level): + if not is_list_like(arr): + raise TypeError(f"{arrname} must be list-like") + if len(arr) > 0 and is_list_like(arr[0]): + raise TypeError(f"{arrname} must be list-like") + level = [level] + arr = [arr] + elif level is None or is_list_like(level): + if not is_list_like(arr) or not is_list_like(arr[0]): + raise TypeError(f"{arrname} must be list of lists-like") + return level, arr