[Python-Dev] Possible patch for functools partial - Interested?

[Cameron Simpson]

On 07May2010 14:53, VanL <van.lindberg at gmail.com> wrote:
| On 5/7/2010 12:41 PM, Steven D'Aprano wrote:
| >> Now, if I write
| >>
| >>     def f1(x,y): return x+y
| >>     def f2(x,y): return x+y
| >>
| >> I don't expect  f1==f2 to be True, even though f1 and f2 behave in
| >> exactly the same way, and indeed it is not.
| 
| This is not what I am getting after; these (IMO) should compare unequal.
| I took a fairly conservative line, testing for identity of functions and
| equality of arguments when converted to a normal form:
| 
|     def __eq__(self, other):
|         try:
|             return ((self.func == other.func) and
|                         (self.args == other.args) and
|                         (self.keywords == other.keywords))
[...]

I think that if you're going to say "identity" above you should have:

    self.func is other.func

in your code.

If you want "==" in your code (and I think you do, since you're implementing
__eq__) you should say "equality" instead of "identity".

I know for functions "==" and "is" currently are equivalent, but we should be
really finicky here about intent, especially since a few messages in the
thread is contemplate testing function for equivalence to one degree or
other. At which point "==" and "is" aren't the same any more.

Cheers,
-- 
Cameron Simpson <cs at zip.com.au> DoD#743
http://www.cskk.ezoshosting.com/cs/

Careful and correct use of language is a powerful aid to straight thinking,
for putting into words precisely what we mean necessitates getting our own
minds quite clear on what we mean.      - W.I.B. Beveridge