Possible Duplicate:
A Transpose/Unzip Function in Python
I have a list that looks like this:
list = (('1','a'),('2','b'),('3','c'),('4','d'))
I want to separate the list in 2 lists.
list1 = ('1','2','3','4')
list2 = ('a','b','c','d')
I can do it for example with:
list1 = []
list2 = []
for i in list:
list1.append(i[0])
list2.append(i[1])
But I want to know if there is a more elegant solution.
>>> source_list = ('1','a'),('2','b'),('3','c'),('4','d')
>>> list1, list2 = zip(*source_list)
>>> list1
('1', '2', '3', '4')
>>> list2
('a', 'b', 'c', 'd')
Edit: Note that zip(*iterable) is its own inverse:
>>> list(source_list) == zip(*zip(*source_list))
True
When unpacking into two lists, this becomes:
>>> list1, list2 = zip(*source_list)
>>> list(source_list) == zip(list1, list2)
True
Addition suggested by rocksportrocker.
list1 = (x[0] for x in source_list)
list2 = (x[1] for x in source_list)
Source: Stackoverflow.com