Roel,
I sent a similar reply in private to someone who may not be listening as their
mind is made up. This points to a serious problem with people not testing
hypotheses adequately.
Perhaps for homework, we can assign a request for a Python program that creates
a random sample of quite a few digit strings of lengths from say 1 to 5 and
compares then to each other as strings and then as integer representations and
prints out whether the two methods match or not. Perhaps that might get them to
discard the hypothesis and be a bity more open.
I still have had to deal with people who want to know why "two" is more than
"three" and truly do not understand that just because a human sees "two" as a
number, that does not mean anything about another human in whose language it
may be "zwei" let alone a computer program not expecting character strings to
mean anything unless programmed to examine them a certain way. And often, the
same people cannot sole a simple puzzle like "SEND" + "MORE" == "MONEY"
-----Original Message-----
From: Python-list <python-list-bounces+avi.e.gross=gmail....@python.org> On
Behalf Of Roel Schroeven via Python-list
Sent: Tuesday, December 12, 2023 3:58 AM
To: python-list@python.org
Subject: Re: A problem with str VS int.
Op 12/12/2023 om 9:22 schreef Steve GS via Python-list:
> With all these suggestions on
> how to fix it, no one seems to
> answer why it fails only when
> entering a two-digit number.
> One and three work fine when
> comparing with str values. It
> is interesting that the
> leading 0 on a two digit
> worked. Still, one digit and
> three digit work but not two.
Three-digit numbers work because you're comparing to another three-digit
numbers. When two integer numbers have the same number of digits, their
lexicographical ordering matches their numeric ordering.
One-digit numbers don't work fine:
>>> "5" < "400"
False
even though we can construct cases where it seems as if they do:
>>> "1" < "400"
True
Two-digit numbers sometimes seem to work:
>>> "30" < "400"
True
But other times clearly don't work:
>>> "50" < "400"
False
String comparison first looks at the first characters of both operands.
If they are different (as in the examples above), their ordering is used
regardless of all the other characters that come after, and regardless
of the length of the string. Try working through some examples (make
sure to pick examples with a wide variety of first digits) and you'll
see why it sometimes seems to work, but very unreliably.
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