[Python-Dev] Octal literals

Guido van Rossum guido at python.org
Mon Feb 6 18:44:32 CET 2006

On 2/6/06, Bengt Richter <bokr at oz.net> wrote:
>  Is PEP 237 phase C to be implemented sooner than py3k,
> making isinstance(<something>, int) a transparently distinction-hiding alias for
> isinstance(<something>, integer), or outright illegal? IOW, will isinstance(<something>, int)
> be _guaranteed_ to be a bug, thus requiring code change? If so, when?

Probably not before Python 3.0. Until then, int and long will be
distinct types for backwards compatibilty reasons. But we want as much
code as possible to treat longs the same as ints, hence the party line
that (barring attenuating circumstances :-) isinstance(x, int) is a
bug if the code doesn't also have a similar case for long. If you find
standard library code (in Python *or* C!) that treats int
preferentially, please submit a patch or bug.

What we should do in 3.0 is not entirely clear to me. It would be nice
if there was only a single type (named 'int', of course) with two
run-time representations, one similar to the current int and one
similar to the current long. But that's not so easy, and somewhat
contrary to the philosophy that differences in (C-level)
representation are best distinguisghed by looking at the type of an
object. The next most likely solution is to make long a subclass of
int, or perhaps to make int an abstract base class with two
subclasses, short and long.

--Guido van Rossum (home page: http://www.python.org/~guido/)

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