[Python-ideas] Implement comparison operators for range objects

[Sven Marnach]

Bruce Leban schrieb am Mi, 12. Okt 2011, um 11:30:17 -0700:
>    Other than unit testing, what are the use cases? If I was writing a unit
>    test, I'd be inclined to be very explicit about what I meant
>    r1 is r2
>    repr(r1) == repr(r2)
>    list(r1) == list(r2)

Even with a useful '==' operator defined, you could still use 'r1 ==
r2' or 'r1 is r2', depending on the intended semnatics, just as with
every other data type.  You just wouldn't need to expand the range to
a list.

Comparing the representations doesn't ever seem useful, though.  The
only way to access the original start, stop and step values is by
parsing the representation, and these values don't affect the
behaviour of the range object in any other way.  Moreover, they might
even change implicitly:

    >>> range(5, 10, 3)
    range(5, 10, 3)
    >>> range(5, 10, 3)[:]
    range(5, 11, 3)

I can't imagine any situation which I would like to consider the above
two ranges different in.

Cheers,
    Sven