How do I split the lists in python

Question

Suppose I have a list ['x1_0','x2_1','x3_0'] How can I split the above list into two lists such that the first list contains ['x1','x2','x3'] and the second list [0,1,0]? i.e.

         ('x1_0')
         /    \
        /      \
       /        \
     1st list   2nd list
      'x1'          0

Feel free to use as many tools as possible. This could obviously done in a single for loop ,which I am aware of. Is there a better way to do this ?. Something which uses list comprehension ? Als

What are `x1_0`? Variable names? – myaut Feb 27 '15 at 10:24 — myaut, Feb 27 '15 at 10:24
I guess, x1 and 0 are two lists as per him. @myaut – Nazaf Anwar Feb 27 '15 at 10:24 — Nazaf Anwar, Feb 27 '15 at 10:24

Mazdak · Accepted Answer · 2015-02-27T11:02:15.250

6

You can use zip and a list comprehension :

>>> zip(*[i.split('_') for i in l])
[('x1', 'x2', 'x3'), ('0', '1', '0')]

And if you want to convert the second tuple's elements to int you can use the following nested list comprehension :

>>> [[int(i) if i.isdigit() else i for i in tup] for tup in zip(*[i.split('_') for i in l])]
[['x1', 'x2', 'x3'], [0, 1, 0]]

The preceding way is the proper way to do this task but as you say in comment as a smaller solution you can use map :

>>> l=[l[0],map(int,l[1])]
>>> l
[('x1', 'x2', 'x3'), [0, 1, 0]]

edited Feb 27 '15 at 11:02

answered Feb 27 '15 at 10:25

Mazdak

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@vks its for unpacking! checkout the link! – Mazdak Feb 27 '15 at 10:29
@vks http://stackoverflow.com/questions/36901/what-does-double-star-and-star-do-for-python-parameters – Carsten Feb 27 '15 at 10:29
how do I convert elements in the second list into integers. – Palash Ahuja Feb 27 '15 at 10:29
@PalashAhuja you can use `int` function,check the edit! – Mazdak Feb 27 '15 at 10:32

vks · Answer 2 · 2015-02-27T10:31:53.910

1

k=["x1_0","x2_1","x3_0"]
k1=[x.split("_")[0] for x in k]
k2=[int(x.split("_")[1]) for x in k]

You can do this simply this way.

edited Feb 27 '15 at 10:31

answered Feb 27 '15 at 10:25

vks

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How do I split the lists in python

2 Answers2