Exercise: Reverse a String (Python)

py-reverse-string

⭐ beginner ⏱️ 10 min

Write a function reverse_str that returns the reverse of a string.

reverse.py

💡 Hints

Hint 1: Slicing

Python slicing supports negative steps. For example: s[::-1].

Hint 2: Built-in reversed

''.join(reversed(s)) returns a reversed string.

⚠️ Try the exercise first! Show Solution

def reverse_str(s: str) -> str:
    return s[::-1]

🧪 Tests

Run these tests locally with:

cargo test

View Test Code

import unittest

class TestReverse(unittest.TestCase):
    def test_reverse(self):
        self.assertEqual(reverse_str("abc"), "cba")
        self.assertEqual(reverse_str(""), "")
        self.assertEqual(reverse_str("a"), "a")

if __name__ == '__main__':
    unittest.main()

🤔 Reflection

Which approach do you prefer: slicing or reversed()?
How would you handle non-ASCII strings? (Hint: Python str is Unicode.)