All base class initializers get called

This code can be used in debugging phase to notice errors sooner. It is usually always desirable to Visit all base class __init__-methods, but Python does nothing to ensure they will be visited. Set AssertInit as a metaclass in the base class of your class hierarchy, and all errors from not calling base class __init__s will be cleanly reported as AssertionErrors. The solution should work properly with multiple inheritance and diamond-shaped inheritance graphs (see the example at the bottom of code). It slows down object creation by a large amount (I`d assume but didn`t do any tests).