I have got a list i.e.
ls= [u'Cancer',u"Men's",u'Orthopedics',u'Pediatric',u"Senior's",u"Women's"]
ls.sort() does not seem to work here due to presence of single quote in the list elements.
I need to sort this list. Any idea???
2 Answers
Actually, the question is valid and the answer is not exactly correct in general case.
If the test material was not already sorted, it would not get correctly alphabetized but the 's would cause the list to be sorted to wrong order:
>>> l = ["'''b", "a", "a'ab", "aaa"]
>>> l.sort()
>>> l
["'''b", 'a', "a'ab", 'aaa']
>>> from functools import partial
>>> import string
>>> keyfunc = partial(string.replace, old="'", new="")
>>> l.sort(key=keyfunc)
>>> l
['a', 'aaa', "a'ab", "'''b"]
3 Comments
Eli Bendersky
If you refer to my answer as not being exactly correct, could you please clarify what exactly isn't correct?
user1170364
kimvais is right..his explanation is more accurate..thanks man
Sven Marnach
@user1170364: Please reconsider. This answer says "the
's would cause the list to be sorted to wrong order", which simply is not true. The truth is that ' is sorted before all alphanumeric characters, which isn't "wrong", but might not be what you want in some given context.>>> ls
[u'Cancer', u"Men's", u'Orthopedics', u'Pediatric', u"Senior's", u"Women's"]
>>> ls.sort()
>>> ls
[u'Cancer', u"Men's", u'Orthopedics', u'Pediatric', u"Senior's", u"Women's"]
Since the list was sorted in the first place, it didn't change. sort has no problem with ' - but note that it sorts before the a-z and A-Z characters:
>>> ls
[u'abc', u'abz', u"ab'"]
>>> ls.sort()
>>> ls
[u"ab'", u'abc', u'abz']
>>>
4 Comments
Kimvais
You can ignore case in sorting by
import string and ls.sort(key=string.lower)Kimvais
This is correct in this exact case, but not generally. @EliBendersky see my example, for example
["a'b", "aa"] won't get correctly alphabetically sorted without a key function.Eli Bendersky
@Kimvais: I truly don't understand what you mean, but hey, if the OP found in your answer what he needed, I don't mind! Good for him.
Kimvais
what I mean is that
aa'b being before aaa is not in alphabetically correct order
ls.sort()simply leaves it unchanged, as expected. What exactly is your problem?does not seem to work: if it's not the order that you expect, show us what order you got!sortedlist = mylist.sort()does not work in any case. Use the builtin sorted if you need a copy of the list, like in:sortedlist = sorted(mylist)