Update app.py

app.py

@@ -29,6 +29,10 @@ dice_types = [
     }
 ]
 
+# Initialize the user's name if it has not been set yet
+if 'name' not in st.session_state:
+    st.session_state.name = ''
+
 # Get user input for the type of dice and number of rolls
 dice_type = st.selectbox('Choose a type of dice', dice_types)
 num_rolls = st.slider('How many times do you want to roll the dice?', 1, 1000000, 1000)
@@ -65,15 +69,22 @@ fig.show()
 
 # Allow user to download roll data as CSV file with their name and dice type
 if st.button('Download Roll Data as CSV'):
-    roll_data = pd.DataFrame({
-        'Roll': rolls,
-        'Count': np.ones(num_rolls),
-        'DiceNumberOfSides': [dice_type['sides']] * num_rolls
-    })
-    filename = f'roll_data_{dice_type["name"].replace(" ", "_")}_{st.session_state.name}.csv'
-    st.download_button(
-        label='Download CSV',
-        data=roll_data.to_csv(index=False),
-        file_name=filename,
-        mime='text/csv'
-    )
+    if st.session_state.name == '':
+        st.warning('Please enter a name before downloading the roll data')
+    else:
+        roll_data = pd.DataFrame({
+            'Roll': rolls,
+            'Count': np.ones(num_rolls),
+            'DiceNumberOfSides': [dice_type['sides']] * num_rolls
+        })
+        filename = f'roll_data_{dice_type["name"].replace(" ", "_")}_{st.session_state.name}.csv'
+        st.download_button(
+            label='Download CSV',
+            data=roll_data.to_csv(index=False),
+            file_name=filename,
+            mime='text/csv'
+        )
+
+# Add UI control for the user's name
+name = st.text_input('What is your name?', value=st.session_state.name)
+st.session_state.name = name