Using itertools to generate combinations from 2 lists

Question

I have two lists [1,2,3] and [4,5,6]. I'd like to generate a list of all combinations as follows using itertools

ResultingList = [[1,4],[1,5],[1,6],[2,4],[2,5],[2,6],[3,4],[3,5],[3,6]]

So far I've only investigated the itertools.combinations function which seems that it can only handle something like this:

list(itertools.combinations([1,2,3,4,5,6],2))

Which outputs an incorrect result. How can I generate ResultingList above?

Thanks

not really... this formulation of the question is much more straightforward and helpful imo — user32882, Jan 12 '18 at 14:00

score 6 · Accepted Answer · edited Jun 20 '20 at 09:12

6

>>> from itertools import product
>>> list(product([1,2,3], [4,5,6]))
[(1, 4), (1, 5), (1, 6), (2, 4), (2, 5), (2, 6), (3, 4), (3, 5), (3, 6)]

For general understaging:

As stated in the docs, product is the equivalent of: ((x,y) for x in A for y in B) where A and B are your input lists

edited Jun 20 '20 at 09:12

Community

answered Jan 12 '18 at 13:50

Or Duan

yup yup thanks. thats how you do it – user32882 Jan 12 '18 at 14:00
And if you must have sublists: `list(map(list, product([1,2,3], [4,5,6])))` – Steven Rumbalski Jan 12 '18 at 14:22

score 2 · Answer 2 · answered Jan 12 '18 at 14:14

2

if you are not importing product from itertools , then you can use this way also

a=[1,2,3]
b=[4,5,6]
c=[]
for i in a:
    for j in b:
        c.append((i,j))
print c

answered Jan 12 '18 at 14:14

Arjun P P

score 1 · Answer 3 · answered Jan 19 '18 at 19:10

1

You can do simply :

print([(i,j) for i in a for j in b])

output:

[(1, 4), (1, 5), (1, 6), (2, 4), (2, 5), (2, 6), (3, 4), (3, 5), (3, 6)]

answered Jan 19 '18 at 19:10

3 Answers3