Iterate Over a Sequence in Reverse Order in Python

Python Sequences includes Strings, Lists, Tuples, etc. We can merge elements of a Python sequence using different ways. Let's see some examples of iteration over a List in reverse order.

Iterate in Reverse Order using while loop

Example

In this example, we have a List as a sequence and iterate it in reverse order using the while loop ?

# Creating a List
mylist = ["Jacob", "Harry", "Mark", "Anthony"]

# Displaying the List
print("List = ",mylist)

# Length - 1
i = len(mylist) - 1

# Iterate in reverse order
print("Display the List in Reverse order = ")
while i >= 0 :
   print(mylist[i])
   i -= 1

Output

List =  ['Jacob', 'Harry', 'Mark', 'Anthony']
Display the List in Reverse order = 
Anthony
Mark
Harry
Jacob

Iterate in Reverse Order using for loop

Example

In this example, we have a List as a sequence and iterate it in reverse order using the for loop ?

# Creating a List
mylist = ["Jacob", "Harry", "Mark", "Anthony"]

# Displaying the List
print("List = ",mylist)

# Iterate in reverse order
print("Display the List in Reverse order = ")
for i in range(len(mylist) - 1, -1, -1):
   print(mylist[i])

Output

List =  ['Jacob', 'Harry', 'Mark', 'Anthony']
Display the List in Reverse order = 
Anthony
Mark
Harry
Jacob

Iterate in Reverse Order using reversed()

Example

In this example, we have a List as a sequence and iterate it in reverse order using the reversed() method ?

# Creating a List
mylist = ["Jacob", "Harry", "Mark", "Anthony"]

# Displaying the List
print("List = ",mylist)

# Iterate in reverse order using reversed()
print("Display the List in Reverse order = ")
[print (i) for i in reversed(mylist)]

Output

List =  ['Jacob', 'Harry', 'Mark', 'Anthony']
Display the List in Reverse order = 
Anthony
Mark
Harry
Jacob

Iterate in Reverse Order using Negative Indexing

Example

In this example, we have a List as a sequence and iterate it in reverse order using negative indexing ?

# Creating a List
mylist = ["Jacob", "Harry", "Mark", "Anthony"]

# Displaying the List
print("List = ",mylist)

# Iterate in reverse order using negative indexing
print("Display the List in Reverse order = ")
[print (i) for i in mylist[::-1]]

Output

List =  ['Jacob', 'Harry', 'Mark', 'Anthony']
Display the List in Reverse order = 
Anthony
Mark
Harry
Jacob