Python isfloat function featured image

Python isfloat function : Fastnumbers API package

We use Python isfloat function in checking whether a string is of float type or not. But it is not a default function with python language. It comes with Fastnumbers API package in python language.

Python isfloat function [ How to use ? ]:

In order to use Python isfloat function, We need to follow the below steps.

Step 1 :

Install the Fastnumbers API module.

pip install fastnumbers


Step 2:

Import the isFloat module from the Fastnumbers module.

from fastnumbers import isfloat


Step 3:

It’s the final step. Here you need to check the string is float or not. Refer to the below syntax for this.


Here the return type for python isfloat function is aa Boolean variable [True, False]. Let’s run the below code and check the output.

Python isFloat() function
Python isFloat() function


There are few other functions available in the FastNumbers python module. Which works in a similar way.

  1. isreal() function to check whether a string is a real number or not.
  2. isint() isreal() function to check whether a string is integer or not.
  3. isintlike()


How to check string is float or not (alternative)? :

option 1 :

We may typecast any string into a Python object with a try-catch box. Here is the code example for that-

try :  
    output= True
except : 
    print("The user Input is not float") 
    output= False


Option 2:

By using type() in python.

input = 17.01
if(type(input ) == float): 
	print('Input is float') 
	print('Input is not float') 

Option 3:

Using isinstance() method.

input = 12.0
output=isinstance(input , float)

Option 4:

See when you convert any absolute integer into int type there will not be any value change ( Magnitude ). But when we convert any float number into an integer object its value must differ. You will understand more when you see the below example.

input= "18.09"
input_int = int(input)
if input== input_int :
    print("The number is not a Float object")
    print("The number is not a Float object")

Conclusion –

Till now we have explored the five different ways to check that the given string is float type object or not. These are the most popular ways to achieve this. Still, if you think to add more details on this. Please comment below.


Data Science Learner Team

Join our list

Subscribe to our mailing list and get interesting stuff and updates to your email inbox.

Thank you for signup. A Confirmation Email has been sent to your Email Address.

Something went wrong.

Thank you For sharing.We appreciate your support. Don't Forget to LIKE and FOLLOW our SITE to keep UPDATED with Data Science Learner