[Python-Dev] [format] Restrict fill characters for numerical values (original) (raw)

Eric Smith eric at trueblade.com
Wed Nov 11 13:39:26 CET 2009

Stefan Krah wrote:

Hi,

I think http://www.python.org/dev/peps/pep-3101/ is too liberal with the choice of fill characters for numerical values. As far as I can see, this is quite legal:

Python 2.7a0 (trunk:76132M, Nov 6 2009, 15:20:35) [GCC 4.1.3 20080623 (prerelease) (Ubuntu 4.1.2-23ubuntu3)] on linux2 Type "help", "copyright", "credits" or "license" for more information.

from decimal import * format(Decimal(4), "9<10")_ _'4999999999'_ _format(Decimal(4), "9>10") '9999999994' format(Decimal(4), "->2") '-4' I propose to disallow digits and '+-' fill characters for numerical values, except for the combination '0, left-padding'. Actually, I'd prefer to allow only whitespace and '0, left-padding'.

Why?

What problem are you trying to prevent that would justify the extra code to implement this and the extra documentation to explain it?

Eric.

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