Update app.py

app.py

@@ -51,7 +51,8 @@ def convert_units(value: float, from_unit: str, to_unit: str) -> str:
         ('F', 'C'): lambda x: (x - 32) * 5/9
     }
     try:
-        func = conversions[(from_unit.lower(), to_unit.lower())]
+        key = (from_unit.strip().lower(), to_unit.strip().lower())
+        func = conversions[key]
         result = func(value)
         return f"{value} {from_unit} = {result:.2f} {to_unit}"
     except KeyError: