How to Reverse a List in Python


In this post you will see three different ways to Reverse a List in Python without the use of any third-party libraries.

  • Reverse a list Using list.reverse() method
  • Reverse a list Using the “[::-1]” list slicing trick to create a reversed copy
  • Reverse a List by Creating a reverse iterator with the reversed() built-in function
Examples:-

Input : Mylist = 	[1,2,3,4,5,6,7,8]
Output :New_List =	[8,7,6,5,4,3,2,1,]

 


Method #1: Reverse a list in Python Using list.reverse() method

  • Each list of Python has a built-in reverse () method that you can call the reverse contents of the list object to in-place.Reversal of the list in-place means that the new list has not been create and copying the existing elements in the reverse order. Instead, it directly modifies the original list object.
  • list.reverse() Reverses the list in-place
  • list.reverse() Fast, doesn’t take up extra memory
  • list.reverse() Modifies the original list
My_list = [1, 2, 3, 4, 5,6,7,8]
My_list.reverse()
print(My_list)

Output:-

[8, 7, 6, 5, 4, 3, 2, 1]

 

 


Method #2: Reverse a list Using the “[::-1]” Slicing Trick to Reverse a Python List

  • “[::-1]” Slicing Creates a reversed copy of the list
  • “[::-1]” Slicing Takes up memory but doesn’t modify the original
My_list = [1, 2, 3, 4, 5,6,7,8]
New_List=My_list[::-1]
print(New_List)

Output:-

[8, 7, 6, 5, 4, 3, 2, 1]

 


Method #3: Reverse a List by Creating a reverse iterator with the reversed() built-in function

  • reversed() Returns an iterator that returns elements in reverse order
  • reversed() Doesn’t modify the original
  • reversed() Might need to be converted into a list object again
My_list = [1, 2, 3, 4, 5,6,7,8]
New_List=list(reversed(My_list))
print(New_List)

Output:-

[8, 7, 6, 5, 4, 3, 2, 1]

 


 

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