Python List reverse()
Python List reverse() is an inbuilt method in the Python programming language that reverses objects of the List in place.
Syntax:
list_name.reverse()
Parameters:
There are no parameters.
Returns:
The reverse() method does not return any value but reverses the given object from the list.
Error:
When anything other than list is used in place of list, then it returns an AttributeError
Example 1: Reverse a List
Python3
# Python3 program to demonstrate the # use of reverse method # a list of numbers list1 = [ 1 , 2 , 3 , 4 , 1 , 2 , 6 ] list1.reverse() print (list1) # a list of characters list2 = [ 'a' , 'b' , 'c' , 'd' , 'a' , 'a' ] list2.reverse() print (list2) |
Output:
[6, 2, 1, 4, 3, 2, 1] ['a', 'a', 'd', 'c', 'b', 'a']
Example 2: Demonstrate the Error in reverse() Method
Python3
# Python3 program to demonstrate the # error in reverse() method # error when string is used in place of list string = "abgedge" string.reverse() print (string) |
Output:
Traceback (most recent call last): File "/home/b3cf360e62d8812babb5549c3a4d3d30.py", line 5, in string.reverse() AttributeError: 'str' object has no attribute 'reverse'
Example 3: Practical Application
Given a list of numbers, check if the list is a palindrome.
Note: Palindrome-sequence that reads the same backward as forwards.
Python3
# Python3 program for the # practical application of reverse() list1 = [ 1 , 2 , 3 , 2 , 1 ] # store a copy of list list2 = list1.copy() # reverse the list list2.reverse() # compare reversed and original list if list1 = = list2: print ( "Palindrome" ) else : print ( "Not Palindrome" ) |
Output:
Palindrome