[Python-Dev] basenumber redux (original) (raw)

Guido van Rossum guido at python.org
Mon Jan 16 16:53:20 CET 2006

On 1/15/06, Alex Martelli <aleaxit at gmail.com> wrote:

Now, today, I have again been bit by the lack of basenumber (by a bug of mine, fixed by adding decimal.Decimal to a long tuple of classes to be passed to an isinstance call -- I hadn't run that particular numeric code of mine since the time of Python 2.3, apparently), so I'm back to pining for it.

As you already suspected, I think a PEP is needed. The intent of basestring was to only be used as the base class for built-in string types. Clearly what you're proposing is different (Decimal is not built-in -- not yet anyway).

Like other posters, I suspect that the best way of detecting numbers might be some other kind of test, not necessarily a call to isinstance().

It would also help to explain the user case more. ("I've been bitten" doesn't convey a lot of information. :-)

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

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