How to check if string input is a number? [duplicate]

Answer 1

If you specifically need an int or float, you could try "is not int" or "is not float":

user_input = ''
while user_input is not int:
    try:
        user_input = int(input('Enter a number: '))
        break
    except ValueError:
        print('Please enter a valid number: ')

print('You entered {}'.format(a))

If you only need to work with ints, then the most elegant solution I've seen is the ".isdigit()" method:

a = ''
while a.isdigit() == False:
    a = input('Enter a number: ')

print('You entered {}'.format(a))