On Thu, Feb 6, 2020 at 11:58 AM Chris Angelico <rosuav@gmail.com> wrote:

That's a simple matter of history.

Python 2.7.13 (default, Sep 26 2018, 18:42:22)
[GCC 6.3.0 20170516] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> 0100

In C and its friends and family, a leading zero means octal. Python 3
removed this (you can use "0o100" for octal, paralleling "0x100" for
hex), but in order to ensure that code would cleanly break rather than
inexplicably giving the wrong result, "001" is an error.

Thank you for this clear and concise explanation. As I explain in the post I promised (in the message you responded to), it was a good idea then, and it might not be a good idea now.

I ask that all follow up to that specific topic go to the new thread: