Entry

I update a class with 'reload (module)'. How can I update the instances too?

How to change class instances behavior via reload?

Jun 27th, 2000 00:55
unknown unknown, Laurent Szyster, Jürgen Hermann

You'd have to find the instance one-by-one. If you manage to get hold
of them, you can set their __class__ attribute to the new class:

>>> class A:
...   def doit(self):print "old"
... 
>>> a=A()
>>> class A:
...   def doit(self):print "new"
... 
>>> a.doit()
old
>>> a.__class__=A
>>> a.doit()
new

--- Alternate ---

You should implement static and dynamic features that you need in 
different modules and use proxy methods.

Like this

-- dtest.py --
def method(self):
    ...

-- test.py --
class test:
    def method(self):
        return dtest.method(self)

And then,

>>> import test, dtest
>>> t = test.test()
>>> reload(dtest)
>>> t.method()

----------------------

Laurent showed you how to do this automatically. Another technique I 
used to DETECT whether the implementation of a class has changed is 
this:

class spam:
    def __init__(self):
        pass

    def checkReload(self):
        return self.__class__ != spam