Python appending array to an array

Apart from + operator there's another way to do the same i.e. extend()

a = [1, 2, 3]
b = [10, 20]

a.append(b) # Output: [1, 2, 3, [10, 20]]
a.extend(b) # Output: [1, 2, 3, 10, 20]

You can use these 2 functions for manipulating a list as per your requirement.

You can append the elements of one list to another with the "+=" operator. Note that the "+" operator creates a new list.

a = [1, 2, 3]
b = [10, 20]

a = a + b # Create a new list a+b and assign back to a.
print a
# [1, 2, 3, 10, 20]


# Equivalently:
a = [1, 2, 3]
b = [10, 20]

a += b
print a
# [1, 2, 3, 10, 20]

If you want to append the lists and keep them as lists, then try:

result = []
result.append(a)
result.append(b)
print result
# [[1, 2, 3], [10, 20]]