Creating function to access elements in a list of lists.

Coding Python Support
1

I have a big list of lists (of lists of lists…,) which I will call A.
A = [b1, b2, b3, b4, b5, …] where bn is a collection of values of properties at frame n. b1 is of the same format as b2, and so on.

I would like to be able to extract A[:][c][d][e][f]…, that is, the list of values in A[i][c][d][e][f]… for every i in range(len(A)).

I currently have a procedure demonstrated here:

import bpy
z = [0,1]
b = [z,[2,3]]
q = [b,b,b]
A = [q,q,q,q]

print(A,'
')

j = 1
k = 0
l = 1
n = [j,k,l]

def Extractor(A,n):
    a = []
    for i in range(len(A)):
        if type(A[i]) == list:
            if type(A[i][n[0]]) == list:
                if type(A[i][n[0]][n[1]]) == list:
                    a.append(A[i][n[0]][n[1]][n[2]])
                else:
                    a.append(A[i][n[0]][n[1]])
            else:
                a.append(A[i][n[0]])
        else:
            a.append(A[i])
    return a;

a = Extractor(A,n)

print(a)

but as you see, there is a limit to how deep I can go with this method. Arbitrarily deep, so long as I write the function long enough, but is there a better way to do this? And what if I want to find A[b][:][d][e][f]…? Is there a more flexible way to extract elements from a known place in a list of lists?

2 

def get(elem,indices):
    for i in indices:
        elem=elem[i]
    return elem

indices=(2,3,4,5,6,7)

#retrieve A[2][3][4][5][6][7]
#
elem=get(A,indices)

#collect A[:][2][3][4][5][6][7]
#
result=[ get(elem, indices) for elem in A  ]

#collect A[2][3][4][:][5][6][7]
#
result=[ get(elem, indices[3:]) for elem in get(A,indices[:3]) ]
3

Ah, thank you.