1def factorial(n):
 2    # This is a comment explaining the function
 3    if n <= 1:
 4        return 1
 5    else:
 6        return n * factorial(n - 1)
 7
 8class Calculator:
 9    def __init__(self):
10        self.result = 0
11
12    def add(self, a, b):
13        """Docstring for add method"""
14        return a + b
15
16if __name__ == "__main__":
17    print("Factorial of 5 is:", factorial(5))
18    calc = Calculator()
19    res = calc.add(10, 20)
20    print(f"Result: {res}")