Shouldn't %06s zero-pad a string?
jepler at unpythonic.net
Thu Feb 13 20:45:10 CET 2003
Python generally takes inspiration for the handling of %-formats from
the C standard.
Here are the results I get, confusing at first:
>>> '%06s' % 'a'
>>> '%06s' % 3
>>> '%06d' % 3
Here's what my printf manual page says about '0':
0 The value should be zero padded. For d, i, o, u,
x, X, a, A, e, E, f, F, g, and G conversions, the
converted value is padded on the left with zeros
rather than blanks. If the 0 and - flags both
appear, the 0 flag is ignored. If a precision is
given with a numeric conversion (d, i, o, u, x, and
X), the 0 flag is ignored. For other conversions,
the behavior is undefined.
so "the behavior is undefined" when the s conversion is used.
The treatment of 0 as " " (space) seems fairly useful, though.
The '%06s' % 3 case makes sense when you remember what Python will do
to produce its output: First, it converts 3 to a string and then
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