[Python-ideas] Implement comparison operators for range objects

[Bruce Leban]

On Wed, Oct 12, 2011 at 1:33 PM, Sven Marnach <sven at marnach.net> wrote:

> 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.
>


def test_copy_range(self):
    """Make sure that every time we call copy_range we get a new identical
copy of the range."""
    a = range(5, 10, 3)
    b = copy_range(a)
    c = copy_range(a)
    self.assert(a is not b)
    self.assert(a is not c)
    self.assert(b is not c)
    self.assert(repr(a) == repr(b))
    self.assert(repr(a) == repr(c))

Anyway, my thought is that if you think this change should be made it would
be helpful to have a use case other than unit tests as for those purposes,
explicit list() or repr() is more clear and performance is not typically an
issue. Why would you normally be comparing ranges at all?

--- Bruce
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