Why do I get AttributeError: 'NoneType' object has no attribute 'something'?

I am getting an error message that says

AttributeError: 'NoneType' object has no attribute 'something'

How can I understand this message?

What general scenarios might cause such an AttributeError, and how can I identify the problem?


This is a special case of AttributeErrors. It merits separate treatment because there are a lot of ways to get an unexpected None value from the code, so it’s typically a different problem; for other AttributeErrors, the problem might just as easily be the attribute name.