[Python-Dev] cmp(x,x)

Tim Peters tim.one at comcast.net
Tue May 25 13:28:52 EDT 2004


[Gustavo Niemeyer]
> I'm wondering what is causing this confusion then:
>
> % ./python
> Python 2.4a0 (#5, May 25 2004, 13:45:26)
> [GCC 3.3.3 (release)] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
> [...]
> >>> l = []
> >>> l == l
> Got in list_richcompare()!
> True
> >>> if l == l: print "foo"
> ...
> Got in list_richcompare()!
> foo

My mistake!  And my apologies.  PyObject_RichCompare() (not ...Bool()) gets
called in this case, and it can't infer anything from object identity alone.
The list object may, but it's quite possible that trying to would cost more
cycles than it saved.




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