PyPandasTruthValueIsAmbiguousInspection

Reports ambiguous usage of a pandas DataFrame or Series in a boolean context, such as if, while, or logical expressions. This typically leads to the runtime error: ValueError: The truth value of a DataFrame is ambiguous.

In pandas, expressions like df or df == other do not return a single boolean value, but rather a DataFrame or Series of booleans. Using these in control flow without explicit reduction (e.g., .any(), .all(), or .empty) is ambiguous and will raise an exception.

Example:

if df: # ❌ Raises ValueError: The truth value of a DataFrame is ambiguous
    print("DataFrame exists")

if not df.empty: # ✅ Checks if DataFrame has any rows
    print("DataFrame exists")

When the quick-fix is applied, the condition is replaced with an appropriate reducer like .any(), .all(), or .empty depending on the context.