Python Program to swap the First and the Last Character of a string

Given a String. The task is to swap the first and the last character of the string.

Examples:

Input: GeeksForGeeks
Output: seeksForGeekG
 
Input: Python
Output: nythoP

Python string is immutable which means we cannot modify it directly. But Python has string slicing which makes it very easier to perform string operations and make modifications. Follow the below steps to swap characters –

1. We initialize a variable start, which stores the first character of the string (string[0])
2. We initialize another variable end that stores the last character (string[-1])
3. Then we will use string slicing, string[1:-1], this will access all the characters from the 2nd position excluding the last character.
4. Then we add these three as required forming a new string that has the first and last characters of the original string swapped. And then we will print it.

Below is the implementation of the above approach:

Python3

def swap(string):

    # storing the first character
    start = string[0]

    # storing the last character
    end = string[-1]

    swapped_string = end + string[1:-1] + start
    print(swapped_string)

# Driver Code
swap("GeeksforGeeks")
swap("Python")

Output

seeksforGeekG
nythoP

Time Complexity: O(k), as string slicing takes O(k)
Auxiliary Space: O(n)

Method : Using lists without slicing

Python3

# swap first and last character
string="GeeksforGeeks"
x=list(string)
temp=x[0]
x[0]=x[-1]
x[-1]=temp
print("".join(x))

Output

seeksforGeekG

Time Complexity: O(n)
Auxiliary Space: O(n)