CODEWITHSUNDEEP
pythonlistinsertcopy
Asiv
Asiv

Reputation: 115

inserting all the elements from a list into specific index of sublist from a second list - python 2

I have 2 lists, and for the A list, which is made up of sublists, I'd like to insert all the elements from a second list, B, into a speciifc index within the sublists.

The two lists are as fallows,

A=[[[a, b], [c, d], [g, h]]
   [[e, f], [g, h], [t, f]]]

B=[[d, c], [e, j]]

The wanted out put would look like this, with each element from B added into the 2nd spot in A,

A=[[[a, b], [d, c], [c, d], [g, h]],
   [[a, b], [e, j], [c, d], [g, h]],
   [[e, f], [d, c], [g, h], [t, f]],
   [[e, f], [e, j], [g, h], [t, f]]]

So for each sublist in A, the elements of B get added into the 2nd spot in A. Im sure there needs to a 'copy' elements, as each sublist in A needs to get copied to account for the 2 different elements in B, but Im not sure how to go about coding this. Any input is appreciated.

Upvotes: 1

Views: 279

Answers (2)

Nicolas Gervais
Nicolas Gervais

Reputation: 36624

I hope you appreciate the half hour I put on this one-liner solution:

[*map(lambda a, b: (a[0], b, a[1:]), *([i for s in [*map(lambda x: (x, x), A)] for i in s], B*2))]

[(['a', 'b'], ['d', 'c'], [['c', 'd'], ['g', 'h']]),
 (['a', 'b'], ['e', 'j'], [['c', 'd'], ['g', 'h']]),
 (['e', 'f'], ['d', 'c'], [['g', 'h'], ['t', 'f']]),
 (['e', 'f'], ['e', 'j'], [['g', 'h'], ['t', 'f']])]

Upvotes: 2

JimmyCarlos
JimmyCarlos

Reputation: 1952

This was a fun challenge! Good question.

def insertInto(A,B,i) -> list:
    output_list = []
    for a_list in A:
        for b_list in B:
            new_list = a_list[::]
            new_list.insert(i-1,b_list)
            output_list.append(new_list)
    return output_list




A=[[["a", "b"], ["c", "d"], ["g", "h"]],
   [["e", "f"], ["g", "h"], ["t", "f"]]]

B=[["d", "c"], ["e", "j"]]

C=[[["a", "b"], ["d", "c"], ["c", "d"], ["g", "h"]],
   [["a", "b"], ["e", "j"], ["c", "d"], ["g", "h"]],
   [["e", "f"], ["d", "c"], ["g", "h"], ["t", "f"]],
   [["e", "f"], ["e", "j"], ["g", "h"], ["t", "f"]]]

assert insertInto(A,B,2) == C

Upvotes: 1

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