need stopping if input not number

Question

my code not stop in line 9-10 when inserted words, I would like it to continue only when numbers are entered

from cs50 import get_int

numbers = []

while True:

    number = get_int("number: ")

    if not number:   #  here  #
        break        #  here  #

    if number not in numbers:
        numbers.append(number)

print()
for number in numbers:
    print(number)

There's no point tagging your question will contradictory Python version numbers. — khelwood, Apr 27 '19 at 13:55
What is `from cs50 import get_int`? What is the `get_int` function here? — Devesh Kumar Singh, Apr 27 '19 at 14:00
We need to know what this `get_int` returns, would throw a exception in case of non int value came through or will return `None`? — MaltMaster, Apr 27 '19 at 14:04

score 0 · Accepted Answer · answered Apr 27 '19 at 14:04

0

You can parse the input string to be a number or not in a while True loop, if it is not a number, break the loop, else keep asking.

numbers = []

while True:

    #Ask for input
    s = input("number: ")
    number = 0

    #Try to parse the string as a number, if you cannot, break the loop
    try:
        number = int(s)
    except:
        break

    #If you can parse the string as a number, add it to the list
    numbers.append(number)

print(numbers)

Sample outputs will be

number: 123
number: 456
number: 789
number: abc
[123, 456, 789]

answered Apr 27 '19 at 14:04

Devesh Kumar Singh

20,259
5
21
40

wow thanks, I did not know some of these functions yet, as' try' and 'except' – Josias Boeno Apr 27 '19 at 14:22
Sorry if this is slightly advanced for you! I can give you something simpler which you might understand! If the answer helped you. Please mark it as accepted :) – Devesh Kumar Singh Apr 27 '19 at 14:24
it is not necessary, although I started this week I managed to understand, thanks! – Josias Boeno Apr 27 '19 at 14:30
sure, no worries! – Devesh Kumar Singh Apr 27 '19 at 14:31

score 0 · Answer 2 · answered Apr 27 '19 at 14:07

0

In Python 3, you can use the following to ensure number is an integer (whole number):

isinstance(number, int)

If either an integer or a float (number with decimals) is allowed, you can use the following:

isinstance(number, (int, float))

I highly recommend reading more about this subject in this answer.

answered Apr 27 '19 at 14:07

Christopher Hart

58
5

i'm starting reading about python in this week, thanks for recommendation, I'll read right now hahaha – Josias Boeno Apr 27 '19 at 14:15

score 0 · Answer 3 · answered Apr 27 '19 at 14:07

You don't need to define a new function to do that.

numbers = []
while True:
    number = input("number: ")
    try:
        number = int(number)
        if number not in numbers:
            numbers.append(number)
    except:
        break   

print (numbers)

score 0 · Answer 4 · answered Apr 27 '19 at 14:08

0

try:
    if number == int(number):
        if number not in numbers:
           numbers.append(number)

except:
    #invalid input will throw you into this block
    break

answered Apr 27 '19 at 14:08

Kaleba KB Keitshokile

1,656
1
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12

need stopping if input not number

4 Answers4