On May 13, 1:02 am, MRAB <goo...@mrabarnett.plus.com> wrote: > John Machin wrote: > > MRAB <google <at> mrabarnett.plus.com> writes: > >> Sort the list, passing a function as the 'key' argument. The function > >> should return an integer for the month, eg 0 for 'jan', 1 for 'feb'. If > >> you want to have a different start month then add > > > and if you don't like what that produces, try subtract :-) > > Oops! > > >> the appropriate > >> integer for that month (eg 0 for 'jan', 1 for 'feb') and then modulo 12 > >> to make it wrap around (there are only 12 months in a year), returning > >> the result. > > Actually, subtract the start month, add 12, and then modulo 12.
Ummm ... 12 modulo 12 is a big fat zero, and Python's % is a genuine modulo operator; unlike that of K&R C, it's defined not to go wobbly on negatives. | >>> [(i - 8 + 12) % 12 for i in range(12)] | [4, 5, 6, 7, 8, 9, 10, 11, 0, 1, 2, 3] | >>> [(i - 8 ) % 12 for i in range(12)] | [4, 5, 6, 7, 8, 9, 10, 11, 0, 1, 2, 3] -- http://mail.python.org/mailman/listinfo/python-list
