Use a class in the context of a different module

Question

I want to modify some classes in the standard library to use a different set of globals the ones that other classes in that module use.

Example

This exampl

Answer 1

If you use Python 3, you can subclass B and redefine the __globals__ attribute of the __init__ method like this:

from module_a import B

function = type(lambda: 0)  # similar to 'from types import FunctionType as function', but faster
my_global = []


class My_B (B):
    __init__ = function(B.__init__.__code__, globals(), '__init__',  B.__init__.__defaults__, B.__init__.__closure__)