isinstance-type-none (FURB168)

Derived from the refurb linter.

Fix is sometimes available.

What it does

Checks for uses of isinstance that check if an object is of type None.

Why is this bad?

There is only ever one instance of None, so it is more efficient and readable to use the is operator to check if an object is None.

Example

isinstance(obj, type(None))

Use instead:

obj is None

Fix safety

The fix will be marked as unsafe if there are any comments within the call.

References

• Python documentation: isinstance
• Python documentation: None
• Python documentation: type
• Python documentation: Identity comparisons