How to recognize if a input is a float

Question

I'm making a calculator in python 3 and I'm wondering if there is an option that can tell if the input the user gave is not a float. For example if the user wrote a word instead of a float the code will recognize it and print out something like:

if num1 != float:
    print("You Need To Enter A Number")

Do you actually care about float or just if it's numeric (i.e. float or int)? — DarrylG, Aug 14 '20 at 14:12

score 0 · Answer 1 · answered Aug 14 '20 at 14:01

0

input() returns everything in str type. You need to manually test by conversion

def is_float(number):
    try:
        float(number)
        return True
    except ValueError:
        return False

number = input()
print(is_float(number))

answered Aug 14 '20 at 14:01

tbhaxor

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This will say that `12` is a float though, which might not be what OP wants – Ted Klein Bergman Aug 14 '20 at 14:02

Ted Klein Bergman · Answer 2 · 2020-08-14T14:09:51.433

I'd just keep it simple. If it contains a dot, say it's a float.

number = input('Number: ')

if '.' in number:
    try:
        value = float(number)
        # Number is a float.
    except ValueError:
        print('Invalid input')
else:
    try:
        value = int(number)
        # Number is an integer.
    except ValueError:
        print('Invalid input')

Although, the best way is probably to use ast.literal_eval as explained in this answer.

How to recognize if a input is a float

2 Answers2