Re: Interesting list Validity (True/False)

En Tue, 15 May 2007 01:37:07 -0300, mensanator@xxxxxxx <mensanator@xxxxxxx> escribió:

> <quote emphasis added>
> Sec 2.2.3:
> Objects of different types, *--->except<---* different numeric types
> and different string types, never compare equal;
> </quote>

The exceptions you mean are not exceptions to "'X==Y' means 'X equals
Y'".

I never said they were. I said they were exceptions to
"Obbjects of different types never compare equal".

This is an unfortunate wording, and perhaps should read: "For most builtin types, objects of different types never compare equal; such objects are ordered consistently but arbitrarily (so that sorting a heterogeneous sequence yields a consistent result). The exceptions being different numeric types and different string types, that have a special treatment; see section 5.9 in the Reference Manual for details."

And said section 5.9 should be updated too: "The objects need not have the same type. If both are numbers or strings, they are converted to a common type. Otherwise, objects of different builtin types always compare unequal, and are ordered consistently but arbitrarily. You can control comparison behavior of objects of non-builtin types by defining a __cmp__ method or rich comparison methods like __gt__, described in section 3.4."

I hope this helps a bit. Your performance issues don't have to do with the *definition* of equal or not equal, only with how someone decided to write the mpz class.

--
Gabriel Genellina

.

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