What is the cleanest way to do a sort plus uniq on a Python list?

Question

Consider a Python list my_list containing ['foo', 'foo', 'bar'].

What is the most Pythonic way to uniquify and sort a list ?
(think cat my_list | sort | uniq)

This is how I currently do it and while it works I'm sure there are better ways to do it.

my_list = [] ... my_list.append("foo") my_list.append("foo") my_list.append("bar") ... my_list = set(my_list) my_list = list(my_list) my_list.sort() 

Answer 1

my_list = sorted(set(my_list)) 

Answer 2

# Python ≥ 2.4 # because of (generator expression) and itertools.groupby, sorted  import itertools  def sort_uniq(sequence):     return (x[0] for x in itertools.groupby(sorted(sequence))) 

Faster:

import itertools, operator import sys  if sys.hexversion < 0x03000000:     mapper= itertools.imap # 2.4 ≤ Python < 3 else:     mapper= map # Python ≥ 3  def sort_uniq(sequence):     return mapper(         operator.itemgetter(0),         itertools.groupby(sorted(sequence))) 

Both versions return an generator, so you might want to supply the result to the list type:

sequence= list(sort_uniq(sequence)) 

Note that this will work with non-hashable items too:

>>> list(sort_uniq([[0],[1],[0]])) [[0], [1]]