if something in list append in another list code example

Example 1: python add all values of another list

a = [1, 2, 3]
b = [4, 5, 6]
a += b
# another way: a.extend(b)

Example 2: append a list to another list as element

a = ['Jon', 'janni', 'Jannardhan']
b = ['28', '29', '30']
a.append(b)
print(a)
a.pop()
a.extend(b)
print(a)