Python Reverse String

Python String doesn’t have a built-in reverse() function. However, there are various ways to reverse a string in Python.

1. How to Reverse a String in Python?

A portion of the normal approaches to turn around a string are:

1-plan designs essentials

• Using Slicing to make a converse duplicate of the string.
• Using for loop and adding characters backward request
• Using while loop to repeat string characters backward request and add them
• Using string join() function with reversed() iterator
• Making a list from the string and afterward calling its reverse() function
• Utilizing Recursion

1.1) Python Reverse String using Slicing

def reverse_slicing(s):
    return s[::-1]

input_str = 'ABç∂EF'

if __name__ == "__main__":
    print('Reverse String using slicing =', reverse_slicing(input_str))

If you run above Python script, the output will be:

Reverse String using slicing = FE∂çBA

1.2) Reverse String using For Loop

def reverse_for_loop(s):
    s1 = ''
    for c in s:
        s1 = c + s1  # appending chars in reverse order
    return s1

input_str = 'ABç∂EF'

if __name__ == "__main__":
    print('Reverse String using for loop =', reverse_for_loop(input_str))

Output: Reverse String using for loop = FE∂çBA

1.3) Reverse a String using While Loop

def reverse_while_loop(s):
    s1 = ''
    length = len(s) - 1
    while length >= 0:
        s1 = s1 + s[length]
        length = length - 1
    return s1

input_str = 'ABç∂EF'

if __name__ == "__main__":
    print('Reverse String using while loop =', reverse_while_loop(input_str))

1.4) Reverse a String using join() and reversed()

def reverse_join_reversed_iter(s):
    s1 = ''.join(reversed(s))
    return s1

1.5) Python Reverse String using List reverse()

def reverse_list(s):
    temp_list = list(s)
    temp_list.reverse()
    return ''.join(temp_list)

1.6) Python Reverse String using Recursion

def reverse_recursion(s):
    if len(s) == 0:
        return s
    else:
        return reverse_recursion(s[1:]) + s[0]

2. Best Way to Reverse a String in Python

We can turn around a string through numerous calculations. We have just observed six of them. However, which of them you ought to decide to switch a string.

We can use timeit module to run numerous emphasess of these capacities and get the normal time needed to run them.

All the above capacities are put away in a python content named string_reverse.py. I executed every one of these capacities individually for multiple times utilizing the timeit module and got the normal of the best 5 runs.

$ python3.7 -m timeit --number 100000 --unit usec 'import string_reverse' 'string_reverse.reverse_slicing("ABç∂EF"*10)'
100000 loops, best of 5: 0.449 usec per loop

$ python3.7 -m timeit --number 100000 --unit usec 'import string_reverse' 'string_reverse.reverse_list("ABç∂EF"*10)'
100000 loops, best of 5: 2.46 usec per loop

$ python3.7 -m timeit --number 100000 --unit usec 'import string_reverse' 'string_reverse.reverse_join_reversed_iter("ABç∂EF"*10)'
100000 loops, best of 5: 2.49 usec per loop

$ python3.7 -m timeit --number 100000 --unit usec 'import string_reverse' 'string_reverse.reverse_for_loop("ABç∂EF"*10)'
100000 loops, best of 5: 5.5 usec per loop

$ python3.7 -m timeit --number 100000 --unit usec 'import string_reverse' 'string_reverse.reverse_while_loop("ABç∂EF"*10)'
100000 loops, best of 5: 9.4 usec per loop

$ python3.7 -m timeit --number 100000 --unit usec 'import string_reverse' 'string_reverse.reverse_recursion("ABç∂EF"*10)'
100000 loops, best of 5: 24.3 usec per loop

The below table presents the results and slowness of an algorithm from the best one.

3. Summary

We should utilize cutting to invert a string in Python. Its code is basic and little and we don’t have to compose our own rationale to turn around the string. Additionally, it’s the quickest method to invert a string as distinguished by the above test executions.