Python sorting

korakot (Korakot Chaovavanich) — Mon, 13 Mar 2006 22:04:01 GMT

list.sort() work in place (doesn't return anything)
If you want a version that return result, use sorted() function.



>>> a = [5, 2, 3, 1, 4]

>>> a.sort()    # become [1, 2, 3, 4, 5]

>>> a.sort(cmp) # same as above



>>> a = "This is a test string from Andrew".split()

>>> a.sort(key=str.lower) # using key is simpler

# ['a', 'Andrew', 'from', 'is', 'string', 'test', 'This']



>>> import operator 

>>> L = [('c', 2), ('d', 1), ('a', 4), ('b', 3)]

>>> sorted(L, key=operator.itemgetter(1))

[('d', 1), ('c', 2), ('b', 3), ('a', 4)]

# itemgetter allows easy Schwartzian transform

3 equivalent ways
- key=operator.itemgetter(1)
- key=lambda x: x[1]
- cmp=lambda a,b: cmp(a[1], b[1])

Learn more at Sorting Howto.

DZone Snippets: cmp code

Python sorting