In Python, how do you change an instantiated objec

Question

Let's say you have an object that was instantiated from a class inside a module. Now, you reload that module. The next thing you'd like to do is make that reload affect that class.

mymodule.py
---
class ClassChange():
    def run(self):
        print 'one'

myexperiment.py
---
import mymodule
from mymodule import ClassChange  # why is this necessary?
myObject = ClassChange()
myObject.run()
>>> one
### later, i changed this file, so that it says print 'two'

reload(mymodule)
# trick to change myObject needed here
myObject.run()
>>> two

Do you have to make a new ClassChange object, copy myObject into that, and delete the old myObject? Or is there a simpler way?

Edit: The run() method seems like a static class style method but that was only for the sake of brevity. I'd like the run() method to operate on data inside the object, so a static module function wouldn't do...

Answer 1

You have to get the new class from the fresh module and assign it back to the instance.

If you could trigger this operation anytime you use an instance with this mixin:

import sys

class ObjDebug(object):
  def __getattribute__(self,k):
    ga=object.__getattribute__
    sa=object.__setattr__
    cls=ga(self,'__class__')
    modname=cls.__module__ 
    mod=__import__(modname)
    del sys.modules[modname]
    reload(mod)
    sa(self,'__class__',getattr(mod,cls.__name__))
    return ga(self,k)