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Groups > comp.lang.python > #24629

Re: moving methods from class to instance of other class

From Terry Reedy <tjreedy@udel.edu>
Subject Re: moving methods from class to instance of other class
Date 2012-06-28 13:57 -0400
References <c376d4cf-c888-4fa9-8d4c-032b80a43947@e20g2000vbm.googlegroups.com>
Newsgroups comp.lang.python
Message-ID <mailman.1616.1340906279.4697.python-list@python.org> (permalink)

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On 6/28/2012 2:59 AM, lars van gemerden wrote:

> class A(object):
>      def __init__(self):
>          self.name = 'a'
>      def do(self):
>          print 'A.do: self.name =', self.name
>
> class B(object):
>      def __init__(self):
>          self.name = 'b'
>
> The question is: How do i move the 'do' method from A to b
 > (resulting in  printing "A.do: self.name = b")?

If you want to move the method from class A to class B
(which is normally more sensible than to instance b of B)

B.do = A.do.im_func  # Python 2
B.do = A.do  # Python 3
b = B()
b.do()
# print (with print adjusted for PY3)
A.do: self.name = b

If you want a B instance to act like an A instance, you can change its 
class (subject to some limitations). The following works.

b = B()
b.__class__ = A
b.do()

If make the change temporary and the reversion automatic, write a 
context manager.

-- 
Terry Jan Reedy


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Thread

moving methods from class to instance of other class lars van gemerden <lars@rational-it.com> - 2012-06-27 23:59 -0700
  Re: moving methods from class to instance of other class Benjamin Kaplan <benjamin.kaplan@case.edu> - 2012-06-28 00:22 -0700
    Re: moving methods from class to instance of other class lars van gemerden <lars@rational-it.com> - 2012-06-28 01:14 -0700
  Re: moving methods from class to instance of other class Terry Reedy <tjreedy@udel.edu> - 2012-06-28 13:57 -0400
  Re: moving methods from class to instance of other class Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-06-28 14:15 -0400

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