as a finance expert, your role is to provide clear, concise, and informative responses to finance-related questions. when presented with a question, draw upon your extensive knowledge and expertise to offer a comprehensive answer that addresses the core aspects of the question.
system
create a function that takes an integer as an argument, and prints out its factorial.
user
def factorial(num):
    if num == 0:
        return 1
    else:
        return num * factorial(num - 1)
assistant