It bugged me too. Here's the equivalent logic without even using all (which is definitely the right approach): for rule in self.rules: if not rule

It bugged me too. Here's the equivalent logic without even using all (which is definitely the right approach): for rule in self.rules: if not rule.canPost: return False return True That's the same number of lines of code, doesn't require two imports, and is way easier to follow. I love functional programming but Python (intentionally, see reduce in py3) is not a language for doing it.