Python – Read Integer from Command Line

Read Integer from Command Line

To read integer from command line in Python, we can use input() builtin function. Since, input() function reads a string from standard input, we can use int() function to convert the string to integer.

The following is a simple code snippet to read an integer into variable x.

x = int(input())

We can also prompt user via input() function.

x = int(input('Enter an integer : '))

Examples

Read integer from user

In the following example, we read an integer from user into variable x, using input() and int() functions.

Python Program

try:
    n = int(input('Enter an integer : '))
    print('N =', n)
except ValueError:
    print('You entered an invalid integer')

Output

Enter an integer : 1254
N = 1254

Now, we shall read two integers from user, add them, and print the result to output.

Python Program

try:
    a = int(input('Enter a : '))
    b = int(input('Enter b : '))
    output = a + b
    print('Sum :', output)
except ValueError:
    print('You entered an invalid integer')

Output

Enter a : 5
Enter b : 4
Sum : 9

Conclusion

In this Python Tutorial, we learned how to read an integer from user, using input() and int() function.