Python – Check if Variable is a Number

In this tutorial, we are going to see how to check if a variable is a Number in Python. As you know, Python’s input() function always converts the user input to a string. i.e. the user input type is always a string. Now let’s look at how to check if the user input is a number or a string. When we say a number, it means that it can be an integer or a float.
 

 

Method 1: Convert the input to int or float

In this approach, we can verify that the input is a number or a string by converting the input to “int” type. If the input is an integer, it can be successfully converted to “int”, and we can say that the input is a number. Otherwise, you get a valueError exception and we can say that the input is a string.

nbr = input ("Enter a number: ")
try:
   val = int(nbr)
   print("The input value is an integer = ", val)
except ValueError:
   print("It is not an integer!")

Output:

Enter a number: 2
The input value is an integer =  2

Enter a number: c
It is not an integer!

 

Method 2: Use the isdigit() method to check if the input is a number or a string

nbr = input ("Enter a number: ")
if( nbr.isdigit()):
    print("The input value is a number")
else:
    print("The input value is a string")

Output:

Enter a number: 10
The input value is a number

Enter a number: char
The input value is a string

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