How to reverse a string in Python?

Reversing a string in Python means creating a new string that is a reversed copy of the original string.

Here are some different ways to reverse a string in Python −

Using slicing

In this example, we use slicing to create a new string that is a reversed copy of the original string. The syntax [start:stop:step] means that we start at the end of the string and step backwards by 1 until we reach the beginning.

Example

original_string = "lorem ipsum"
reversed_string = original_string[::-1]
print(reversed_string)

Output

muspi merol

Using a for loop

In this example, we use a ‘for loop’ to iterate over the characters of the original string in reverse order. We start at the last character (index len(original_string)-1) and move backwards by 1 until we reach the first character (index 0). We then add each character to a new string called reversed_string.

Example

original_string = "lorem ipsum"
reversed_string = ""

for i in range(len(original_string)-1, -1, -1):
   reversed_string += original_string[i]

print(reversed_string)

Output

muspi merol

Using the reversed() function

In this example, we use the built-in reversed() function to create a reverse iterator over the characters of the original string. We then use a ‘for loop’ to iterate over the iterator and add each character to a new string called reversed_string.

Example

original_string = "lorem ipsum"
reversed_string = ""

for char in reversed(original_string):
   reversed_string += char

print(reversed_string)

Output

muspi merol

Using recursion

In this example, we define a recursive function called reverse_string that takes a string as input and returns a reversed copy of the string. The function works by calling itself recursively with the first character removed from the input string (s[1:]) and then adding the first character to the end of the reversed substring (s[0]). The recursion stops when the length of the input string reaches zero.

Example

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

original_string = "lorem ipsum"
reversed_string = reverse_string(original_string)
print(reversed_string)

Output

muspi merol

Using a while loop

In this example, we use a while loop to iterate over the characters of the original string in reverse order. We start at the last character by setting the index to len(original_string) - 1, and we continue looping as long as the index is greater than or equal to zero. Inside the loop, we add each character to a new string called reversed_string, and we decrement the index by one on each iteration.

Example

original_string = "lorem ipsum"
reversed_string = ""
# Start with the last character of the original string
index = len(original_string) - 1
# Loop backwards over the string and add each character to the new string
while index >= 0:
   reversed_string += original_string[index]
   index -= 1
print(reversed_string)

Output

muspi merol

Using a list and the join() method

In this example, we first convert the original string to a list of characters using the list() function. We can then use the reverse() method of the list to reverse the order of the characters in place. Finally, we use the join() method of an empty string to concatenate the characters back into a new string called reversed_string.

Example

original_string = "lorem ipsum"
character_list = list(original_string)
# Reverse the list using the reverse() method
character_list.reverse()
# Convert the list back to a string using the join() method
reversed_string = "".join(character_list)
print(reversed_string)

Output

muspi merol