Lists in Python - Each array in different row

Question

how can I create a new list with the following format.

The 3 arrays inside each row should be in different rows.

a= [['111,0.0,1', '111,1.27,2', '111,3.47,3'],
    ['222,0.0,1', '222,1.27,2', '222,3.47,3'],
    ['33,0.0,1', '33,1.27,2', '33,3.47,3'],
    ['44,0.0,1', '44,1.27,2', '4,3.47,3'],
    ['55,0.0,1', '55,1.27,2', '55,3.47,3']]

Final desired ouput:

 b=[['111,0.0,1', 
  '111,1.27,2', 
  '111,3.47,3',
  '222,0.0,1', 
  '222,1.27,2', 
  '222,3.47,3',
  '33,0.0,1', 
  '33,1.27,2', 
  '33,3.47,3',
  '44,0.0,1',
  '44,1.27,2',
  '44,3.47,3',
  '55,0.0,1', 
  '55,1.27,2', 
  '55,3.47,3']]

score 1 · Accepted Answer · answered May 03 '19 at 19:04

1

Is this what you are looking for?

b = [[j for i in a for j in i]]

answered May 03 '19 at 19:04

Fariborz Ghavamian

809
2
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oh yeah! thats exactly what I was looking for. Thanks! – lolo May 03 '19 at 19:06

score 1 · Answer 2 · answered May 03 '19 at 19:06

To be clear, there is no concept of rows vs. columns in Python. Your end result is just a big list of str's, within another list.

You can create the big list by chaining all of the original small lists together (a[0] + a[1] + ...), for which we may use

import itertools
big_list = list(itertools.chain(*a))

To put this inside another list,

b = [big_list]

Lists in Python - Each array in different row

2 Answers2