how to concatenate two list code example

Example 1: python concatenate lists

a = [1, 2, 3]
b = [4, 5]

# method 1:
c = a + b # forms a new list with all elements
print(c) # [1, 2, 3, 4, 5]

# method 2:
a.extend(b) # adds the elements of b into list a
print(a) # [1, 2, 3, 4, 5]

Example 2: merge lists in list python

import itertools
a = [['a','b'], ['c']]
print(list(itertools.chain.from_iterable(a)))