Python: string to a list of lists

Question

I'm new to python and confused about converting a string to a list. I'm unsure how to create a list within a list to accomplish the following:

Ex.

string = '2,4,6,8|10,12,14,16|18,20,22,24'

I'm trying to use split() to create a data structure, my_data, so that when I input

print my_data[1][2] #it should return 14

Stuck: This is what I did at first:

new_list = string.split('|')  #['2,4,6,8', '10,12,14,16,', '18,20,22,24']

And I know that you can't split a list so I split() the string first but I don't know how to convert the strings within the new list into a list in order to me to get the right output.

You can't .split a list but you can split the strings inside the list which is what I have done — jamylak
– jamylak, Commented Aug 10, 2012 at 5:10
+1 for such a well-written question! You actually tried to solve your problem, posted what you had tried, and then asked for specific help on where to go next - bravo! — PaulMcG
– PaulMcG, Commented Aug 10, 2012 at 7:29

jamylak · Accepted Answer · 2012-08-10 05:19:33Z

23

>>> text = '2,4,6,8|10,12,14,16|18,20,22,24'
>>> my_data = [x.split(',') for x in text.split('|')]
>>> my_data
[['2', '4', '6', '8'], ['10', '12', '14', '16'], ['18', '20', '22', '24']]
>>> print my_data[1][2]
14

Maybe you also want to convert each digit (still strings) to int, in which case I would do this:

>>> [[int(y) for y in x.split(',')] for x in text.split('|')]
[[2, 4, 6, 8], [10, 12, 14, 16], [18, 20, 22, 24]]

edited Aug 10, 2012 at 5:19

answered Aug 10, 2012 at 5:06

jamylak

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1 Comment

user1589244 Over a year ago

Thank you so much!!! I like the first way you did this. I'm not looking to convert each digit to int but I see why one would do that.

Ashwini Chaudhary · Accepted Answer · 2012-08-10 05:26:23Z

2

>>> strs = '2,4,6,8|10,12,14,16|18,20,22,24'
>>> strs1=strs.split('|')
>>> [map(int,x.split(',')) for x in strs1] 
[[2, 4, 6, 8], [10, 12, 14, 16], [18, 20, 22, 24]]

Note: for python 3.x use list(map(int,x.split(','))), as map() returns a map object in python 3.x

edited Aug 10, 2012 at 5:26

answered Aug 10, 2012 at 5:17

Ashwini Chaudhary

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