How can I sum a list of numbers?

Question

My program needs to read a set of integers from the user and store them in a list. It should read numbers from the user until the user enters 0 to quit. Then it needs to add them up and display the sum to the user. If the user types anything that is not an integer, it needs to display an error to the user.

I'm having a hard time figuring out how to make a list that the user can infinitely input numbers into.

From what I have tried to do and looked up, I've only been able to make a defined list and make a program that takes in a specific amount of inputs.

This is what I have. Obviously, it doesn't work, but it shows what I'm going for.

n, ns = 0, 0  # count of numbers, sum of numbers
print("Enter numbers or any other 0 to quit.")

while(1):
     grades = input("enter = ")
     if (int):
          ns += int
          n += 1
     else:
          if (0):
               print(ns)
          break

You need to provide a base code. At least you need to try :) — Netwave
– Netwave, Commented Mar 11, 2019 at 3:06
Welcome to SO, please read: stackoverflow.com/help/how-to-ask and stackoverflow.com/help/mcve if you want to get help on this platform. — Allan
– Allan, Commented Mar 11, 2019 at 3:06

Om A. · Accepted Answer · 2019-03-11 03:20:19Z

1

Use this:

list_of_nums = []
loop = True
while loop == True:
    try: num = int(input("Enter Integer: "))
    except ValueError: num = "invalid"
    if num == "invalid": print("\nPlease Print A Valid Integer!\n");
    elif num != 0: list_of_nums.append(num)
    else: loop = False
print("\nSum of Inputed Integers: " + str(sum(list_of_nums)) + "\n")

answered Mar 11, 2019 at 3:20

Om A.

1406 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Hano Over a year ago

Thank you, This makes a lot more sense to me now. I've never knew about try or except so this helps a ton. Also they way you've looped the code makes much more sense. But i'm still confused on why list_of_sums is equal to empty brackets. Would making it equal to zero work too? And could you make the value have a starting number if you wanted? Thanks again.

Om A. Over a year ago

That's great - list_of_sums is [] because if you want to append a value to it each time, you have to tell python that it is initialized as a list first - so setting it to zero would not work. And you could definitely initialize it with a starting number - ex. [5]

Hano Over a year ago

So saying list_of_sums = () wouldn't work? or would it make it something else?

Om A. Over a year ago

No that wouldn't work, because that would tell python that you are initializing it as a tuple.

Crazy-Kaleidoscope-7 · Accepted Answer · 2019-03-11 03:20:47Z

0

Python 3

lists=[]
while(True):
    i=int(input("Enter The Input"))
    if i==0:
        break
    else:
        lists.append(i)
print(lists)

answered Mar 11, 2019 at 3:20

Crazy-Kaleidoscope-7

3901 gold badge2 silver badges17 bronze badges

Collectives™ on Stack Overflow

How can I sum a list of numbers?

2 Answers 2

4 Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

4 Comments

Comments

Related