Python | Convert a nested list into a flat list

The task is to convert a nested list into a single list in python i.e no matter how many levels of nesting is there in python list, all the nested has to be removed in order to convert it to a single containing all the values of all the lists inside the outermost brackets but without any brackets inside.

Examples:

Input : l = [1, 2, [3, 4, [5, 6] ], 7, 8, [9, [10] ] ]
Output : l = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

Input : l = [[[‘item1’, ‘item2’]], [[‘item3’, ‘item4’]]]
Output : l = [‘item1’, ‘item2’, ‘itm3, ‘item4”]

We use recursion because the levels of nesting cannot be predetermined.



filter_none

edit
close

play_arrow

link
brightness_4
code

# Python code to flat a nested list with
# multiple levels of nesting allowed.
  
# input list
l = [1, 2, [3, 4, [5, 6]], 7, 8, [9, [10]]]
  
# output list
output = []
  
# function used for removing nested 
# lists in python. 
def reemovNestings(l):
    for i in l:
        if type(i) == list:
            reemovNestings(i)
        else:
            output.append(i)
  
# Driver code
print ('The original list: ', l)
reemovNestings(l)
print ('The list after removing nesting: ', output)

chevron_right


Output:

The original list:  [1, 2, [3, 4, [5, 6]], 7, 8, [9, [10]]]
The list after removing nesting:  [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course.

My Personal Notes arrow_drop_up


If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.