Get All Pairs From Elements In Sublists

I have a list of sublists. I need all possible pairs between the elements in the sublists. For example, for a list like this: a=[[1,2,3],[4,5],[6]] The result should be: result=

Solution 1:

You can do the following

>>> from itertools import chain
>>> a=[[1,2,3],[4,5],[6]]
>>> b=[]
>>> for index, item in enumerate(a):
...    b.extend([[i, j] for i in item for j in chain.from_iterable(a[index+1:])])
>>> b
[[1, 4],
 [1, 5],
 [1, 6],
 [2, 4],
 [2, 5],
 [2, 6],
 [3, 4],
 [3, 5],
 [3, 6],
 [4, 6],
 [5, 6]]

Solution 2:

from itertools import chain, product, combinations

sublists = [[1, 2, 3], [4, 5], [6]]
pairs = chain.from_iterable(
    product(*sublist_pair) for sublist_pair in combinations(sublists, 2)
)
for x, y in pairs:
    print(x, y)

Solution 3:

# create an empty set to store unique sublist elements
initSet = set()

# combine all sublist elements
for sublist in a:
    tempSet = set(sublist)
    initSet = intiSet.union(tempSet)

initSet = list(initSet)
# find all possible non-repeating combinations
for _element in initSet:
    combinations = list()
    for i in range(1, len(initSet) - 1):
        combinations.append([_element, initSet[i]]
    initSet.pop(0)

#result stored in combinations