On Fri, Jul 24, 2015 at 4:23 PM, Gregory Ewing <greg.ew...@canterbury.ac.nz> wrote: > 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.
So, the definition of a number is: Something on which you perform numeric operations. Aside from being circular, wouldn't this mean that "rope" is a number, since its square root is string? ChrisA -- https://mail.python.org/mailman/listinfo/python-list
