"a in b" calls a.__cmp__, why?

[Gerrit Holl]

Terry Reedy wrote:
> "Gerrit Holl" <gerrit at nl.linux.org> wrote in message
> news:mailman.1056224677.5103.python-list at python.org...
> > Why does a container-sequence's __contains__ call obj.__cmp__?
> 
> Because 'in' is defined by equality, as determined by comparison
> returning 0 or not ,  and not by identity.

Ah, thanks... I'll override __eq__ then to compare by equality.

> If you want identity in-ness, either program the search yourself or
> use a list  (or dict/set) of ids and search for id(item) in idlist.
> 
> If your list is long (enough) and repeatedly searched, sorting and
> using binsearch or making a set or dict for hash access will be
> faster.

I will try that.
Thanks!

yours,
Gerrit.

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