[Python-Dev] n.numbits: method or property? (original) (raw)

Mark Dickinson dickinsm at gmail.com
Wed Nov 12 19:19:57 CET 2008

[Antoine Pitrou]

No, but Python is duck-typed and alternate integer classes could adopt such an implementation while trying to respect the Python-level long API.

Good point. That makes me feel a little uneasy about adding numbits at all. Though I guess there are other parts of Python's integer API that are inherently linked to a binary representation, namely, the bit operations and shifts. And there'd be no requirement for alternative integer types to implement numbits (it wouldn't be part of the Integral ABC, for example).

[Aahz]

What do you call Decimal? ;-)

Um. A stdlib module? I guess I should have said that I can't see Python adopting a nonbinary implementation for the 'int/long' types.

It is fun to dream about, though: there are some definite advantages to an internal decimal representation---notably, faster str <-> int conversion. And it turns out that overall performance doesn't suffer: I've coded up a Python extension module that implements decimal integers (stored internally in base 10**9) whose performance handily beats that of the current binary int/long.

Mark

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