For example, I have array like this
[
[1,2,3],
[4],
[5,6],
]
I want to generate all combinations from the list above, which if it should look something like this.
[1, 4, 5]
[1, 4, 6]
[2, 4, 5]
[2, 4, 6]
[3, 4, 5]
[3, 4, 6]
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3 Answers
Sounds like you want product from the built-in itertools library
>>> import itertools
>>> list(itertools.product([1, 2, 3], [4], [5, 6]))
[(1, 4, 5), (1, 4, 6), (2, 4, 5), (2, 4, 6), (3, 4, 5), (3, 4, 6)]
>>>
>>> columns = [[1,2,3],
[4],
[5,6]]
>>> list(itertools.product(*columns))
[(1, 4, 5), (1, 4, 6), (2, 4, 5), (2, 4, 6), (3, 4, 5), (3, 4, 6)]
Comments
Here you go:
a = [1,2,3]
b = [4]
c = [5,6]
d = [[x, y, z] for x in a for y in b for z in c]
Comments
To make a Cartesian product you just need to iterate in all dimensions in this case
For example:
for x in dimension_x:
for y in dimension_y:
for z in dimension_z:
use the x,y,z
The complexity of the algorithm will always be tough (for 2 arrays -> n2, for 3 -> n3, ..., for M -> n^M where n is the length of the longest array).
Note that you have duplicates: (a,b) is the same as (b,a). So you can change the algorithm to work faster if you don't need the duplicates.