nested list into one list python code example

Example 1: python convert nested list to list of strings

# Basix syntax:
['delim'.join([str(elem) for elem in sublist]) for sublist in my_list]
# Where delim is the delimiter that will separate the elements of the
#	nested lists when they are flattened to a list of strings

# Note, this uses two "levels" of list comprehension

# Example usage 1:
my_list = [[1, '1', 1], [2,'2',2], [3,'3',3]]
[' '.join([str(elem) for elem in sublist]) for sublist in my_list]
--> ['1 1 1', '2 2 2', '3 3 3'] # List of space-delimited strings

# Example usage 2:
my_list = [[1, '1', 1], [2,'2',2], [3,'3',3]]
['_'.join([str(elem) for elem in sublist]) for sublist in my_list]
--> ['1_1_1', '2_2_2', '3_3_3'] # List of underscore-delimited strings

Example 2: convert 2 level nested list to one level list in python

>>> from collections import Iterable
>>> def flat(lst):
...     for parent in lst:
...         if not isinstance(i, Iterable):
...             yield parent
...         else:
...             for child in flat(parent):
...                 yield child
...
>>> list(flat(([1,[2,2,2],4]))
[1, 2, 2, 2, 4]

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"