[kstrauser]

You should absolutely be using `is` where appropriate. `x is None` is almost always preferable to `x == None`. If you're checking for object identity, use `is`. If equality, use `==`. They're different use cases.

[maweki]

Especially since == can be overwritten, while 'is' can not.

[kstrauser]

That's right. Any class can define its own __eq__ method.