A note about the ordering of mixin classes
In Python, when you have a class that inherits from both a primary class and some mixin classes (for example, if you're using the SocketServer stuff), it's conventional to declare your class's inheritance list with the primary class first:
class Real(primary, mixin1, mixin2): ....
However, an important safety tip: if your mixin class overrides methods of the primary class, it has to be first. Failure to observe this safety tip can cause head-scratching bugs followed by head-smacking embarrassment.
(Since I was mixing stuff in to standard types like
str, I spent a certain amount of time wondering if the interpreter
had special direct magic for them that meant I couldn't hijack and
augment their standard behavior. I felt somewhat foolish when there
turned out to be a much simpler explanation.)