Reverse a String in Python

Reverse a String in Python

One of the most common Python interview questions is reversing a string. Python makes this elegant with slicing.

The Pythonic Way

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

# Example
print(reverse_string("hello"))  # Output: "olleh"

How It Works

The slicing syntax s[::-1] means: start from the end, go to the beginning, step by -1 (backwards). It is the most concise and readable solution.

Alternative: Using a Loop

def reverse_string_loop(s):
    result = ""
    for char in s:
        result = char + result
    return result

print(reverse_string_loop("hello"))  # Output: "olleh"

Alternative: Using reversed()

def reverse_string_builtin(s):
    return "".join(reversed(s))

print(reverse_string_builtin("hello"))  # Output: "olleh"

Key Takeaway

Use s[::-1] for simplicity and performance. It is the standard Pythonic approach widely accepted in interviews and production code.