python flatten nested lists code example

Example 1: flatten a list of list python

# idiomatic python

# using itertools
import itertools

list_of_list = [[1, 2, 3], [4, 5], [6]]
chain = itertools.chain(*images)

flattened_list = list(chain)
# [1, 2, 3, 4, 5, 6]

Example 2: python unlist flatten nested lists

import collections.abc

def flatten(x):
    if isinstance(x, collections.Iterable): # or isinstance(x,list)
        return [a for i in x for a in flatten(i)]
    else:
        return [x]

Example 3: python nested list

# example of a nested list
my_list = [[1, 2], ["one", "two"]]

# accessing a nested list
my_list[1][0] # outputs "one"

Example 4: python nested list

L = [[1, 2, 3],[4, 5, 6],[7, 8, 9]]   
for list in L:
    for number in list:
        print(number, end=' ')
# Prints 1 2 3 4 5 6 7 8 9