how do i check an input for an integer in python?

The int() function can convert a given string integer value to an integer type. It raises an error if the desired value is not an integer and cannot be converted. We can use this method to check if the user’s string is an integer or not, as shown below.

user_input = input("Enter the input ")

try:
int(user_input)
it_is = True
except ValueError:
   it_is = False

print(it_is)

Enter the input 15
True

The following code shows how we can use this function to check if a string contains integers in Python.

user_input = input("Enter the input ")

print(user_input.isnumeric())

5._

import re

user_input = input("Enter the input ")

num_format = re.compile(r '^\-?[1-9][0-9]*$')
it_is = re.match(num_format, user_input)

if it_is: print("True")
else: print("False")

Suggestion : 2

Last Updated : 20 Jun, 2022

Output:

100
<class 'str'>
   <class 'int'>

Suggestion : 3

How to get a list of numbers as input in Python,In this tutorial, we will learn how to check if user input is a string or number in Python., How to take input from the user until they enter valid input in Python?,Also read: Python program to check whether given number is Hoax Number

Type 1: type(num) to check input type in Python

num = input("Enter Something:")
print(type(num))

Type2: isnumeric() function to check if a number is integer or not in Python

Thing = input("Enter Something:")
if Thing.isnumeric():
   print("Entered Thing is Integer:", Thing)
else:
   print("Entered Thing is Not an Integer")

Output:

Enter Something: 123

Entered Thing is Integer: 123

Enter Something: abc

Entered Thing is Not an Integer

Type4: isdigit() function in Python

thing = 123
if thing.isdigit():
   print("It is Integer")
else:
   print("It is Not a Integer")

Suggestion : 4

In this way, we can check if the variable is an integer in python.,In this Python tutorial, we will discuss how to check if the variable is an integer in Python. We will also check:,Python check if the variable is an integer,To check if the variable is a list or a tuple in Python, we can use type() to check the data type of a variable in python.

Example:

my_variable = 56
print(isinstance(my_variable, int))

Example:

# In N.py
n = 12
print('Saying hello in N')

Example:

# In M.py
from N
import n
print('The value of n is %s in M' % str(n))

Suggestion : 5

To understand this example, you should have the knowledge of the following Python programming topics:,Here, we have used the if...elif...else statement. We can do the same thing using nested if statements as follows.,In this example, you will learn to check whether a number entered by the user is positive, negative or zero. This problem is solved using if...elif...else and nested if...else statement.,Python if...else Statement

Source Code: Using if...elif...else

num = float(input("Enter a number: "))
if num > 0:
   print("Positive number")
elif num == 0:
   print("Zero")
else:
   print("Negative number")

Source Code: Using Nested if

num = float(input("Enter a number: "))
if num >= 0:
   if num == 0:
   print("Zero")
else:
   print("Positive number")
else:
   print("Negative number")

Output 1

Enter a number: 2
Positive number