python computing hierarchy

        Factorial refers to the multiplication of all integers from 1 to a positive integer n, that is, n! = 1 × 2 × 3 × … × n. Here is the Python code to calculate the hierarchy:

def factorial(n):
    """
    计算阶层
    :param n: 正整数
    :return: n的阶层
    """
    if n == 1 or n == 0:
        return 1
    else:
        return n * factorial(n-1)

        Usage example:

print(factorial(5)) # 输出120，即5的阶层