Problem with checking if input is integer (very beginner)

Question

I'm just starting to learn Python (it's my first language). I'm trying to make a simple program that checks if the number the user inputs is an integer.

My code is:

number = input('Insert number: ')

if isinstance(number, int):
    print('INT')
else:
    print('NOT')

I have no idea why, but every number gets it to print 'NOT'. If I just make a statement 'number = 1' in the code, it prints 'INT', but if I input '1' in the console when the program asks for input, it prints 'NOT' no matter what. Why is that?

(I'm using Python 3.8 with PyCharm)

"I have no idea why, but every number gets it to print 'NOT'" because input() function takes the input in form of a **string** — muyustan, Jun 15 '20 at 22:00
Does this answer your question? [How do I check if a string is a number (float)?](https://stackoverflow.com/questions/354038/how-do-i-check-if-a-string-is-a-number-float) — muyustan, Jun 15 '20 at 22:01
Does this answer your question? [How can I read inputs as numbers?](https://stackoverflow.com/questions/20449427/how-can-i-read-inputs-as-numbers) - [`input`](https://docs.python.org/3/library/functions.html#input) returns a string — wwii, Jun 15 '20 at 22:09

Red · Accepted Answer · 2020-06-15T22:10:58.460

2

When you input something, the type is always a str. If you try:

number = input('Insert number: ')

if isinstance(number, str):
    print('INT')
else:
    print('NOT')

you will always get:

INT

If all you want is to detect whether the input is an integer, you can use str.isdigit():

number = input('Insert number: ')

if number.isdigit():
    print('INT')
else:
    print('NOT')

edited Jun 15 '20 at 22:10

answered Jun 15 '20 at 22:03

Red

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Problem with checking if input is integer (very beginner)

1 Answers1