On 07/22/2015 07:51 AM, Grant Edwards wrote: > On 2015-07-22, Ben Finney <ben+pyt...@benfinney.id.au> wrote: >> Laura Creighton <l...@openend.se> writes: >> >>> The biggest use I have for decimal numbers that begin with 0 is in >>> credit card numbers, account numbers and the like where the first >>> check you do is 'does this thing have the correct number of digits'. >> >> The following are examples of types from the real world that people >> think of, and casually discuss, as “numbers”. >> >> * Postal code >> * Credit card number >> * Telephone number >> * Car registration plate number >> * Personal Identification Number (PIN) > > Those are all strings. Not numbers.
That depends. 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, and possibly to identify what kind of card it is. -- https://mail.python.org/mailman/listinfo/python-list
