Reverse Strings in Python

An image tutorial on reversing strings in Python. Explore step-by-step methods for reversing text and manipulating data.

How to reverse strings in Python

  • There is no specific method of the str object to reverse a string in Python like the list reverse method, you may use a number of techniques to reverse a string.
  • One of the ways is using the extended slice.
  • The second way the is reversed() method with join() for reversing a string.
  • You may also use the slice object for reversing a given string.
  • A loop can also be used to reverse a string.
  • The following section explains how to reverse string with code snippets.

First method of Python reverse string: The extended slice

The extended slice is a technique that enables you to slice the data of objects like strings in Python programs. It takes three values i.e.

object[start:stop:step]

The object can be a string, list, tuple, etc.

For our topic of this tutorial, reversing a string, we will use the string object.

An example of completely reversing a string

To completely reverse a string by using the extended slice technique, just provide the step value as -1 and leave the other two values as follows:

#Reversing a string example


str_reverse = "Hello, This is Python Lesson"

print ("The reversed string: ", str_reverse[::-1])

Output:

The reversed string: nosseL nohtyP si sihT ,olleH

In the output graphic, you can see the order of the given string is reversed completely.

Reversing only a part of the string

If you require reversing only a part of the string then you may specify the start, end, and step parameters for setting the position within the string.

The negative values for all will play the trick.

See this example where only the word “Python” is reversed from the above example string:

#Reversing a string partially example

str_reverse = "Hello, This is Python Lesson"

print ("The partial reversed string: ", str_reverse[-8:-15:-1])

Output:

The partial reversed string: nohtyP

Using slice objects for reversing a string

You may also use the slice objects for reversing the string objects. The slice object is different from the extended slice. It uses the following syntax:

slice(start ,stop ,step)

You may learn more about both and see the difference here.

The slice object uses the parenthesis and values are separated by commas. See an example below for reversing a string by using the slice object:

#Reversing a string by slice object

str_reverse = "slice object for reversing a String"

str_slice = slice(-1,-39, -1)
print("Original String:" ,str_reverse)
print("Reversed after slice object:" ,str_reverse[str_slice])

Result:

Original String: slice object for reversing a String
Reversed after slice object: gnirtS a gnisrever rof tcejbo ecils

Using reversed function with join()

Another way of reversing the string is using the reversed function with join(). The reversed() takes a sequence as argument and returns a reversed iterator.

This iterator (string in our case) is used in the join function that concatenates the string by a given sequence.

See a demo below of reversing a string by using these two functions:

#Reversing a string by reversed and join functions

str_src = "Reversed and join"

reversed_str = ''.join(reversed(str_src))

print("Original String:" ,str_src)

print("String after revsered with join:" ,reversed_str)

Output:

Python- reversed join

The Final Word

Of all the above solutions to reverse strings, the recommended is using the extended slice. This is more efficient and straightforward.

You may try other solutions like using a while loop or creating your own function for academic purposes.

Author - Atiq Zia

Atiq is the writer at jquery-az.com, an online tutorial website started in 2014. With a passion for coding and solutions, I navigate through various languages and frameworks. Follow along as we unravel the mysteries of coding together!