Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.python > #31444

Re: overriding equals operation

References <76D03718A3233B4C8CC236C169B535B5A23DFDFB43@AUSP01VMBX08.collaborationhost.net>
Date 2012-10-16 21:51 -0400
Subject Re: overriding equals operation
From Dwight Hutto <dwightdhutto@gmail.com>
Newsgroups comp.lang.python
Message-ID <mailman.2306.1350438716.27098.python-list@python.org> (permalink)

Show all headers | View raw


On Tue, Oct 16, 2012 at 9:51 AM, Pradipto Banerjee
<pradipto.banerjee@adainvestments.com> wrote:
> I am trying to define class, where if I use a statement a = b, then instead of "a" pointing to the same instance as "b", it should point to a copy of "b", but I can't get it right.
>
> Currently, I have the following:
>
> ----
>
> class myclass(object):
>         def __init__(self, w3kschoolsname='')
>                 self.name = name
>
>         def copy(self):
>                 newvar = myclass(self.name)
>                 return newvar
>
>         def __eq__(self, other):
>                 if instance(other, myclass):
>                         return self == other.copy()
>                 return NotImplemented
> ----
>
> Now if I try:
>
>>>> a=myclass()
>>>> a.name = 'test'
>>>> b=a
>>>> b.name
> 'test'
>>>> b.name = 'test2'
>>>> a.name
> 'test2'
>
> I wanted b=a to make a new copy of "a", but then when I assigned b.name = 'test2', even a.name became 'test2'.
>
> How can I rectify my code to make the __eq__() behave like copy()?
>
> Thanks
>
>
>

If I'm understanding correctly(quick look at it), then write a new py
file and __import__ it if I'm remember correctly.

Use a secondary file to rewrite the existing nature of the python code
file, then import it, and utilize the remade secondary py file for
your usage..
-- 
Best Regards,
David Hutto
CEO: http://www.hitwebdevelopment.com

Back to comp.lang.python | Previous | Next | Find similar | Unroll thread


Thread

Re: overriding equals operation Dwight Hutto <dwightdhutto@gmail.com> - 2012-10-16 21:51 -0400

csiph-web