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

NoneType means that instead of an instance of whatever Class or Object you think you're working with, you've actually got None. That usually means that an assignment or function call up above failed or returned an unexpected result.

You have a variable that is equal to None and you're attempting to access an attribute of it called 'something'.

foo = None
foo.something = 1

or

foo = None
print(foo.something)

Both will yield an AttributeError: 'NoneType'

The NoneType is the type of the value None. In this case, the variable lifetime has a value of None.

A common way to have this happen is to call a function missing a return.

There are an infinite number of other ways to set a variable to None, however.

Consider the code below.

def return_something(someint):
 if  someint > 5:
    return someint

y = return_something(2)
y.real()

This is going to give you the error

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

So points are as below.

1. In the code, a function or class method is not returning anything or returning the None
2. Then you try to access an attribute of that returned object(which is None), causing the error message.