Writing a program from 1 to n that does addition or factorial of number inputted

Question

My code doesn't do the math when in a function definition but I dont know why. When i do it separate without the definitions it works fine but when calling an if with the function definitions it produces results as 0 or 1

#Write a program that asks the user for a number n and gives them the possibility to choose
# between computing the sum and computing the product of 1,…,n.
def summation(n):
    adding = 0
    while n != 0:
        adding += n
        n -= 1
    print(adding)

def factorial(n):
    product = 1
    while n != 0:
        product *= n
        n -= 1
    print(product)

n =0
num = int(input("Enter a number: "))
choice = int(input("Would you like Sum(1) or Product(2)"))

if choice == 1:
     summation(n)

if choice == 2:
    factorial(n)

Answer 1

There is only one mistake in your code . You are taking the number from user in 'num' variable & pass the 'n' into the summation & factorial function which has the value '0'.

Now you can run this code .

def summation(n):
    adding = 0
    while n != 0:
        adding += n
        n -= 1
    print(adding)

def factorial(n):
    product = 1
    while n != 0:
        product *= n
        n -= 1
    print(product)

n =0
num = int(input("Enter a number: "))
choice = int(input("Would you like Sum(1) or Product(2)"))

if choice == 1:
     summation(num)

if choice == 2:
    factorial(num)