New submission from Guido van Rossum <gu...@python.org>:
I sometimes like to use format specs like "%-10s" % foo, which left-aligns the string foo in a field of 10 spaces: >>> '%10s' % foo ' abc' >>> foo = 'abc' >>> '%-10s' % foo 'abc ' This is documented in "Format Specification Mini-Language": https://docs.python.org/3/library/string.html#format-specification-mini-language However it does not work with format() and f-strings: >>> format(foo, '10s') 'abc ' >>> format(foo, '-10s') Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: Sign not allowed in string format specifier >>> f'{foo:10}' 'abc ' >>> f'{foo:-10}' Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: Sign not allowed in string format specifier In each case, without a sign it works, and right-aligns. What am I missing? ---------- messages: 342421 nosy: gvanrossum priority: normal severity: normal status: open title: Can't left-align strings using f-strings or format() type: behavior versions: Python 3.5, Python 3.6, Python 3.7, Python 3.8, Python 3.9 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue36912> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
