python concat list of lists into one 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 two lists python

>>> l1 = [1, 2, 3]
>>> l2 = [4, 5, 6]
>>> joined_list = [*l1, *l2]  # unpack both iterables in a list literal
>>> print(joined_list)
[1, 2, 3, 4, 5, 6]