Comparing things to None the wrong way

Per the PEP 8 Style Guide, the preferred way to compare something to None is the pattern if Cond is None. This is only a guideline. It can be ignored if needed. But the purpose of the PEP 8 style guidelines is to improve the readability of code.


The statement below uses the equality operator to compare a variable to None. This is not the PEP 8 preferred approach to comparing values to None.

number = None

if number == None:
    print("This works, but is not the preferred PEP 8 pattern")

Best practice

Compare values to None using the pattern if cond is None

The code below uses the PEP 8 preferred pattern of if cond is None.

number = None

if number is None:
    print("PEP 8 Style Guide prefers this pattern")

Here the identity operator is is used. It will check whether number is identical to None. is will return to True only if the two variables point to the same object.