Flatten a list of lists of tuples

Question

I have read several posts on the question "how to flatten lists of lists of lists ....". And I came up with this solution:

points = [[[(6,3)],[]],[[],[]]] 
from itertools import chain
list(chain.from_iterable(points))

However my list looks sometimes like this:

[[[(6,3)],[]],[[],[]]]

Not sure if it is correct but I hope you understand.

The point is the leaf element is a tuple and when calling the above code it also removes the tuple and just returns [6,3].

So what could i do to just get [(6,3)] ?

Did you try this solution: http://stackoverflow.com/a/40547477/1904113 ? As it only flattens lists, this should work for you. — MKesper, Mar 07 '17 at 09:19
whenever you are posting a question better you provide the input and output also. Thanks — Anand Tripathi, Mar 07 '17 at 09:22
I just tried your code and got back [[(6, 3)], [], [], []], and not [6,3] as you describe... — ntg, Mar 07 '17 at 10:04

score 1 · Answer 1 · answered Mar 07 '17 at 09:46

1

How about this,

lists = [[[(6,3)],[]],[[],[]]] 

r = [t for sublist in lists for l in sublist for t in l]

print(r)
# [(6, 3)]

answered Mar 07 '17 at 09:46

SparkAndShine

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score 0 · Accepted Answer · answered Mar 07 '17 at 09:39

maybe its not the best solution, but it works fine:

def flat(array):
    result = []
    for i in range(len(array)):
        if type(array[i]) == list:
            for j in flat(array[i]):
                result.append(j)
        else:
            result.append(array[i])
    return result     

print flat([[[(6,3)],[]],[[],[]]] )

and the result is:

>>> 
[(6, 3)]
>>>

Flatten a list of lists of tuples

2 Answers2