> And another one, I typoed a variable name as groups_keys instead of group_keys (or vice-versa, I don't remember). Instead of just throwing an error, Python ha

> And another one, I typoed a variable name as groups_keys instead of group_keys (or vice-versa, I don't remember). Instead of just throwing an error, Python happily went along with it, used an uninitialized value, and then all the logic broke. Python doesn't have uninitialized values, it throws NameError when you try to access a variable that hasn't been set. So I don't see how this could have happened.