Python - get combination of data from array of arrays

Question

I have an array which holds other arrays which are holding possible values of data at given position. Example:

data = [['A'],['A','B'],['A','B'],['A','B','D'],['0','2']]

From this data possible values are (for example):

"AAAA0"  # (00000)  
"AAAA2"  # (00001)  
"AAAD0"  # (00020)

and so on.
What I would need, is to get all possible combinations of data from those single arrays, but order of data is important:

data from inner array can only be placed on its position in outer array (in above example on first position only 'A' can be placed)

Is there some Python module that will be able to handle this (I found itertools, but it's doing not exactly what I need), or maybe someone has some idea how to do this ?

This is not a code-writing service. Could you show us some code that you have tried so we can say what the problems are? You need to show more effort of your own. — Rory Daulton
– Rory Daulton, Commented Jul 31, 2016 at 22:45
I've tried this: import itertools print (list(itertools.combinations([['A'],['B','C'],['D','E','F']], 2))) with result: [(['A'], ['B', 'C']), (['A'], ['D', 'E', 'F']), (['B', 'C'], ['D', 'E', 'F'])] — name
– name, Commented Jul 31, 2016 at 22:46
Possible duplicate of Get the cartesian product of a series of lists in Python — donkopotamus
– donkopotamus, Commented Jul 31, 2016 at 22:58

akuiper · Accepted Answer · 2016-07-31 22:51:30Z

1

I think you need the itertools.product here:

import itertools
[''.join(p) for p in itertools.product(*data)]

#['AAAA0',
# 'AAAA2',
# 'AAAB0',
# 'AAAB2',
# 'AAAD0',
# 'AAAD2',
# 'AABA0',
# 'AABA2',
# 'AABB0',
# 'AABB2',
# 'AABD0',
# 'AABD2',
# 'ABAA0',
# 'ABAA2',
# 'ABAB0',
# 'ABAB2',
# 'ABAD0',
# 'ABAD2',
# 'ABBA0',
# 'ABBA2',
# 'ABBB0',
# 'ABBB2',
# 'ABBD0',
# 'ABBD2']

answered Jul 31, 2016 at 22:51

akuiper

216k33 gold badges362 silver badges379 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

name Over a year ago

That seems to do exactly what I needed. Thank for fast help to all who responded. Also answer of David Gomes was helpful, but this one-liner does the job.

David Gomes · Accepted Answer · 2016-07-31 22:50:35Z

Try this:

data = [['A'], ['A','B'], ['A','B'], ['A','B','D'], ['0','2']]
size = 5

def rec(cur):
    if len(cur) == size:
        print(cur)
        return

    for x in data[len(cur)]:
        rec(cur + [x])

rec([])

Output:

['A', 'A', 'A', 'A', '0']
['A', 'A', 'A', 'A', '2']
['A', 'A', 'A', 'B', '0']
['A', 'A', 'A', 'B', '2']
['A', 'A', 'A', 'D', '0']
['A', 'A', 'A', 'D', '2']
['A', 'A', 'B', 'A', '0']
['A', 'A', 'B', 'A', '2']
['A', 'A', 'B', 'B', '0']
['A', 'A', 'B', 'B', '2']
['A', 'A', 'B', 'D', '0']
['A', 'A', 'B', 'D', '2']
['A', 'B', 'A', 'A', '0']
['A', 'B', 'A', 'A', '2']
['A', 'B', 'A', 'B', '0']
['A', 'B', 'A', 'B', '2']
['A', 'B', 'A', 'D', '0']
['A', 'B', 'A', 'D', '2']
['A', 'B', 'B', 'A', '0']
['A', 'B', 'B', 'A', '2']
['A', 'B', 'B', 'B', '0']
['A', 'B', 'B', 'B', '2']
['A', 'B', 'B', 'D', '0']
['A', 'B', 'B', 'D', '2']

Collectives™ on Stack Overflow

Python - get combination of data from array of arrays

2 Answers 2

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related