What are the elegant ways to do MixIns in Python?
- by Slava Vishnyakov
I need to find an elegant way to do 2 kinds of MixIns.
First:
class A(object):
def method1(self):
do_something()
Now, a MixInClass should make method1 do this: do_other() - A.method1() - do_smth_else() - i.e. basically "wrap" the older function. I'm pretty sure there must exist a good solution to this.
Second:
class B(object):
def method1(self):
do_something()
do_more()
In this case, I want MixInClass2 to be able to inject itself between do_something() and do_more(), i.e.: do_something() - MixIn.method1 - do_more(). I understand that probably this would require modifying class B - that's ok, just looking for simplest ways to achieve this.
These are pretty trivial problems and I actually solved them, but my solution is tainted.
Fisrt one by using self._old_method1 = self.method1(); self.method1() = self._new_method1(); and writing _new_method1() that calls to _old_method1().
Problem: multiple MixIns will all rename to _old_method1 and it is inelegant.
Second MixIn one was solved by creating a dummy method call_mixin(self): pass and injecting it between calls and defining self.call_mixin(). Again inelegant and will break on multiple MixIns..
Any ideas?
