dict generator question
Boris Borcic
bborcic at gmail.com
Fri Sep 19 06:15:58 EDT 2008
Gerard flanagan wrote:
> George Sakkis wrote:
..
>>
>> Note that this works correctly only if the versions are already sorted
>> by major version.
>>
>
> Yes, I should have mentioned it. Here's a fuller example below. There's
> maybe better ways of sorting version numbers, but this is what I do.
Indeed, your sort takes George's objection too litterally, what's needed for a
correct endresult is only that major versions be grouped together, and this is
most simply obtained by sorting the input data in (default) string order, is it
not ?
>
>
> data = [ "1.2.2.2", "1.2.2.3", "1.3.1.2", "1.1.1.1", "1.3.14.5",
> "1.3.21.6" ]
>
> from itertools import groupby
> import re
>
> RXBUILDSORT = re.compile(r'\d+|[a-zA-Z]')
>
> def versionsort(s):
> key = []
> for part in RXBUILDSORT.findall(s.lower()):
> try:
> key.append(int(part))
> except ValueError:
> key.append(ord(part))
> return tuple(key)
>
> data.sort(key=versionsort)
> print data
>
> datadict = \
> dict((k, len(list(g))) for k,g in groupby(data, lambda s: s[:3]))
> print datadict
>
>
>
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>
More information about the Python-list
mailing list