Cartesian product of two lists in python letters and numbers

Question

current

list1 = ['A','B','C']
list2 = [1,2,3]

Desired

list 3 = [['A', 1], ['A', 2], ['A', 3], ['B', 1], ['B', 2],['B', 3],
 ['C', 1], ['C', 2], ['C', 3]]

What I have tried

list3 = [l+str(n) for l in list1 for n in list2]

results in:

['A1', 'A2', 'A3', 'B1', 'B2', 'B3', 'C1', 'C2', 'C3']

`list3 = [[l,str(n)] for l in list1 for n in list2]` note the brackets around the first part — d_kennetz, May 23 '19 at 19:41

score 1 · Accepted Answer · answered May 23 '19 at 19:42

1

You were close:

[[l,n] for l in list1 for n in list2]

answered May 23 '19 at 19:42

Scott Hunter

48,888
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60
101

score 0 · Answer 2 · answered May 23 '19 at 19:44

0

[[l]+[n] for l in list1 for n in list2]

answered May 23 '19 at 19:44

Nithin Reddy

56
3

score -1 · Answer 3 · answered May 23 '19 at 19:42

-1

As Mark has already mentioned, itertools.product would be the way to go. But if you want to continue to use a list comprehension, the correct line would be

list3 = [ [l, str(n)] for l in list1 for n in list2 ]

answered May 23 '19 at 19:42

Koustav Samaddar

51
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Cartesian product of two lists in python letters and numbers

3 Answers3