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From: Gregory Ewing <greg.ewing@canterbury.ac.nz>
Newsgroups: comp.lang.python
Subject: Re: Integers with leading zeroes
Date: Fri, 24 Jul 2015 18:23:09 +1200
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Michael Torrie wrote:
> A credit card number is indeed a number, and there are
> mathematical formulas for determining if a particular number is a valid
> (as in well-formed) credit card number,

If you're talking about the check-digit algorithm,
that doesn't treat the whole number as an integer,
it works on the individual digits:

http://www.datagenetics.com/blog/july42013/

> and possibly to identify what kind of card it is.

That's determined by the leading digits, and can
be done just as well by treating them as characters.

-- 
Greg