CODEWITHSUNDEEP
pythonindexing
Yair
Yair

Reputation: 909

Finding the index of entries in lists of lists, with duplication and sub-lists

I am trying to find the index of elements that contain similar entries in lists of lists. Data might contained duplicated entries as well as sub-lists. For example:

list_A = [['A',[1],'a',],['B',[2],'b'],['C',[3],'c'],['D',[4],'d'],['E',[5],'e'],['A',[1],'a',]]
list_B = [['A','a'],['E','e']]

The desired output should be:

[0, 4, 5]

Upvotes: 0

Views: 57

Answers (3)

Pulsar
Pulsar

Reputation: 288

If you eliminate the inner lists from each element in list_A, you can compare the elements directly with list_B:

list_A = [['A',[1],'a'], ['B',[2],'b'], ['C',[3],'c'], ['D',[4],'d'], 
          ['E',[5],'e'], ['F',[6],'f']]
list_B = [['A','a'],['D','d'],['E','e']]

new_A = ([a, b] for a, _, b in list_A)
common = [i for i, x in enumerate(new_A) if x in list_B]

If you're sure that each element of list_B is uniquely present, then the following works too:

new_A = [[a, b] for a, _, b in list_A]
common = [new_A.index(x) for x in list_B]

Upvotes: 0

Gsk
Gsk

Reputation: 2945

If you need the number shown at index 1, you can use:

res = []

for lb in list_B:
    for la in list_A:
        if all([x in la for x in lb]):
            res.append(la[1][0])

print sorted(res)

# OUTPUT: [1, 1, 5]

if you want the index in list_A, you should use:

res = []

for lb in list_B:
    for n, la in enumerate(list_A):
        if all([x in la for x in lb]):
            res.append(n)

print sorted(res)

# OUTPUT: [0, 4, 5]

Upvotes: 1

Mehrdad Pedramfar
Mehrdad Pedramfar

Reputation: 11083

Try this:

import itertools

list_A = [['A',[1],'a',],['B',[2],'b'],['C',[3],'c'],['D',[4],'d'],['E',[5],'e'],['A',[1],'a',]]
list_B = [['A','a'],['E','e']]

desired_output = []
for i,j in itertools.product(enumerate(list_A),list_B):
     if all(k in i[1] for k in j):
         desired_output.append(i[0])

output:

[0, 4, 5]

Upvotes: 1

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