Python | Shift last element to first position in list

The cyclic rotations have been discussed in the earlier articles. But sometimes, we just require a specific task, a part of rotation i.e shift last element to first element in list. This has the application in day-day programming in certain utilities. Let’s discuss certain ways in which this can be achieved.

Method #1 : Using list slicing and “+” operator
The combination of these functions can be used to perform the task of a single shift in list. The last element is added to the rest of the list to achieve this task using slicing.

# Python3 code to demonstrate
# shift last element to first
# using list slicing and "+" operator

# initializing list
test_list = [1, 4, 5, 6, 7, 8, 9, 12]

# printing the original list
print ("The original list is : " + str(test_list))

# using list slicing and "+" operator
# shift last element to first
test_list = test_list[-1:] + test_list[:-1]

# printing result
print ("The list after shift is : " + str(test_list))

Output:

The original list is : [1, 4, 5, 6, 7, 8, 9, 12]
The list after shift is : [12, 1, 4, 5, 6, 7, 8, 9]

Method #2 : Using insert() + pop()
This functionality can also be achieved using the inbuilt functions of python viz. insert() and pop(). The pop function returns the last element and that is inserted at front using the insert function.

# Python3 code to demonstrate
# shift last element to first
# using insert() + pop()

# initializing list
test_list = [1, 4, 5, 6, 7, 8, 9, 12]

# printing the original list
print ("The original list is : " + str(test_list))

# using insert() + pop()
# shift last element to first
test_list.insert(0, test_list.pop())

# printing result
print ("The list after shift is : " + str(test_list))

Output:

The original list is : [1, 4, 5, 6, 7, 8, 9, 12]
The list after shift is : [12, 1, 4, 5, 6, 7, 8, 9]