python - Instantiate children class from parent without changing parent code -

first of all, here (pseudo) code:

somemodule.py:

class parentclass(object):     def __init__(self):         if(not prevent_infinite_reursion) #just make shure not problem ;)             self.somefunction()      def somefunction():          # ... deep down in function ...          # want "monkey patch" call constructor of childclass,          # not parentclass         parentclass()  

othermodule.py

from somemodule import parentclass  class childclass(parentclass):     def __init__(self):         # ... preprocessing ...          super(childclass, self).__init__() 

the problem is, want monkey patch parent class, call constructor of childclass, without changing code of somemodule.py. doesn't matter if it's patched in class instance(that's shure better) or globally.

i know can override somefunction, contains many lines of code, being sane.

thanks!

you use mock.patch this:

class childclass(parentclass):     def somefunction(self):         patch('somemodule.parentclass', childclass):             super(childclass, self).somefunction()