# Why Python don't accept 03 as a number?

Chris Angelico rosuav at gmail.com
Mon Dec 10 06:08:30 EST 2018

```On Mon, Dec 10, 2018 at 9:46 PM <jfong at ms4.hinet.net> wrote:
>
> Chris Angelico於 2018年12月10日星期一 UTC+8下午6時17分14秒寫道：
> > On Mon, Dec 10, 2018 at 9:11 PM Antoon Pardon <antoon.pardon at vub.be> wrote:
> > >
> > > On 10/12/18 11:03, Chris Angelico wrote:
> > > > Considering that, in a problem of that description, neither S nor M
> > > > may represent zero, I don't think there's a problem here.
> > >
> > > Not all such problems have that condition.
> >
> > They should. Every published set of problems that I've ever solved by
> > hand has. I went searching online for some, and found this page:
> >
> > http://puzzlepicnic.com/genre?alphametic
> >
> > which clearly states that exact restriction. The implication is that
> > you're solving a puzzle in arithmetic (usually addition or long
> > multiplication), and it is *exactly* as you would have written it with
> > digits, save that the digits have been replaced with letters (and
> > carries have been omitted, since that'd make it too easy). You
> > wouldn't write a leading zero on a number in standard grade-school
> > arithmetic, so you also won't use a leading zero in anything here.
> >
> > ChrisA
>
> All I know is that when I write a number 03, there is no any human being will say it's an illegal number.
>

Yet most human beings will agree that you don't write out an
arithmetic problem as:

0 1 9 8
+   7 1 3
=========

> I prefer to buy the reason that this restriction was bring in is because of the puzzle's author know it will cause trouble without this, not because of our written habit.
>

No, it's a restriction because it is unsatisfactory without it. The
point of a puzzle is to be fun, and fun means having restrictions that
fit what people expect.

ChrisA
```