I can. A project I've been involved with a bit lately has several of bugs of the form "I expected X but got None" where None was a rare case. Or using `if not f

I can. A project I've been involved with a bit lately has several of bugs of the form "I expected X but got None" where None was a rare case. Or using `if not foo` instead of `if foo is not None`, where the actual error can occur very far away from the if statement. A type system is a good way to get static analysis and documentation :)