ValueError: The truth value of a DataFrame is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all()

ValueError: The truth value of a DataFrame is ambiguous. This error occurs when you try to use a DataFrame in a conditional statement, such as an if statement, where a single boolean value is expected. Since a DataFrame can contain multiple values, it is not clear how to interpret the truth value of the entire DataFrame.

To resolve this error, you can use one of the following methods to obtain a single boolean value from the DataFrame:
1. Use the `.empty` attribute: This returns `True` if the DataFrame is empty, and `False` otherwise.
2. Use the `.bool()` method: This returns `True` if all elements in the DataFrame are `True`, and `False` otherwise.
3. Use the `.any()` method: This returns `True` if any element in the DataFrame is `True`, and `False` otherwise.
4. Use the `.all()` method: This returns `True` if all elements in the DataFrame are `True`, and `False` otherwise.
5. Use the `.item()` method: This returns the single value contained in the DataFrame if it contains only one element. If the DataFrame contains more than one element or is empty, it will raise an error.

Please note that you need to choose the appropriate method based on your specific use case and the desired behavior.