I'm trying to create combinations of two lists. List A should be increasing, or a sliding window if you will. List B is static. Where List A can have any number of values.

My question seems to be a different than what I see already posted, as I am using a sliding window on one list and keeping the other list static, so it's not as simple as every combination of both lists.

So the inputs it would look like the below:

ListA = [Val1, Val2, Val3]
ListB = [0, 1]

Giving the below output:

[Val1, 0]
[Val1, 1]
[Val2, 0]
[Val2, 1]
[Val3, 0]
[Val3, 1]

[[Val1, 0], [Val2, 0]]
[[Val1, 0], [Val2, 1]]
[[Val1, 1], [Val2, 0]]
[[Val1, 1], [Val2, 1]]

[[Val1, 0], [Val3, 0]]
[[Val1, 0], [Val3, 1]]
[[Val1, 1], [Val3, 0]]
[[Val1, 1], [Val3, 1]]

[[Val2, 0], [Val3, 0]]
[[Val2, 0], [Val3, 1]]
[[Val2, 1], [Val3, 0]]
[[Val2, 1], [Val3, 1]]

[[Val1, 0], [Val2, 0], [Val3, 0]]
[[Val1, 0], [Val2, 0], [Val3, 1]]
[[Val1, 0], [Val2, 1], [Val3, 0]]
[[Val1, 0], [Val2, 1], [Val3, 1]]
[[Val1, 1], [Val2, 0], [Val3, 0]]
[[Val1, 1], [Val2, 0], [Val3, 1]]
[[Val1, 1], [Val2, 1], [Val3, 0]]
[[Val1, 1], [Val2, 1], [Val3, 1]]

I've been experimenting with itertools combinations and product for a while now, I cannot get my head around it. Covid brain fog :D. Any help would be appreciated.

Thanks

CodePudding user response：

I imagine there's a cleaner way to do this, but this works.

from itertools import chain, combinations, product

A = ['v1', 'v2', 'v3']
B = [0, 1]

for i in chain.from_iterable(combinations(A, k 1) for k in range(len(A))):   
    print([list(zip(i,j)) for j in product(B,repeat=len(i))])

print()

In the for loop, we loop over the powerset of A (excluding the empty set). So (v1), (v2), (v3), (v1,v2), (v1,v3), (v2,v3), (v1,v2,v3).

product(B,repeat=len(i)) is all permutations (allowing repeats) of elements of B of len(i). So if i = (v1,v2), we would get ((0,0),(0,1),(1,0),(1,1)).

Finally, loop through those permutations and zip each one with i. Repeat for all elements of the powerset.

CodePudding user response：

Its complicated to understand this increasing combinations but once you understand it, you will feel it easy

Let me help you to understand the logic behind this

from itertools import combinations

listA = ["Val1", "Val2", "Val3"]
listB = [0, 1]

def perm(l, k):
    n, p = l
    res = l
    prev_gen = (i for i in res)
    for i in range(1, k 1):
        res = (f'{j}{i}' for i in prev_gen for j in (n, p))
        prev_gen = res
    return res

# 3C1 * 2   3C2 * 2^2   3C3*2^3
for idx, _ in enumerate(listA, 1):
    for j in combinations(listA, idx):
        for k in perm(listB, idx-1):
            print(list(zip(j, map(int, str(k)))))

This is the code to generate all possible combinations. I tried to understand the pattern behind this and I found the following pattern in this

If len(list1) = 3 and len(list2) = 2 then it will look like

3C1*2^1 3C2*2^2 3C3 * 2^3

So with this approach, I tried to build the combinations.

output from above code

[('Val1', 0)]
[('Val1', 1)]
[('Val2', 0)]
[('Val2', 1)]
[('Val3', 0)]
[('Val3', 1)]
[('Val1', 0), ('Val2', 0)]
[('Val1', 1), ('Val2', 0)]
[('Val1', 0), ('Val2', 1)]
[('Val1', 1), ('Val2', 1)]
[('Val1', 0), ('Val3', 0)]
[('Val1', 1), ('Val3', 0)]
[('Val1', 0), ('Val3', 1)]
[('Val1', 1), ('Val3', 1)]
[('Val2', 0), ('Val3', 0)]
[('Val2', 1), ('Val3', 0)]
[('Val2', 0), ('Val3', 1)]
[('Val2', 1), ('Val3', 1)]
[('Val1', 0), ('Val2', 0), ('Val3', 0)]
[('Val1', 1), ('Val2', 0), ('Val3', 0)]
[('Val1', 0), ('Val2', 1), ('Val3', 0)]
[('Val1', 1), ('Val2', 1), ('Val3', 0)]
[('Val1', 0), ('Val2', 0), ('Val3', 1)]
[('Val1', 1), ('Val2', 0), ('Val3', 1)]
[('Val1', 0), ('Val2', 1), ('Val3', 1)]
[('Val1', 1), ('Val2', 1), ('Val3', 1)]