How can I check for NaN values in Python?

I’m working with a Pandas dataframe, and I want to check if there are any NaN values in it. What’s the best way to do this?

I’ve tried using isnull() but I’m not sure if that’s the best way to check for NaN values. Can someone provide a more accurate way to do this? Here’s my code so far:

This returns a dataframe with True values where the NaNs are. Is there a better way to do this, or is isnull() the recommended method? Thanks in advance for your help!