How To Check If A Float Variable Is Empty In Python?

If you are a Python programmer, you might encounter these requirements for checking whether a float variable is empty. In this tutorial, I will explain various methods to check if a float variable is empty in Python with examples.

To check if a float variable is empty by determining if it is None in Python, you can use a simple if statement. For example, if float_var is the variable, you can write if float_var is None: to check if it is None. If the condition is true, the variable is considered empty. This method is straightforward and effective for identifying uninitialized or explicitly set None float variables.

What is “Empty” in Python

Let us first understand what is empty in Python.

None: The variable is explicitly set to None.
NaN: The variable is set to Not a Number, which is a special floating-point value.
Zero: The variable has a value of 0.0.

Method 1: Check for None

A variable that is None is often considered empty. You can check if a float variable is None using a simple if statement in Python. Here is an example.

# Example of checking for None
float_var = None

if float_var is None:
    print("The variable is None.")
else:
    print("The variable is not None.")

If float_var is None, the output will be “The variable is None.” Otherwise, it will print “The variable is not None.”

I executed the above Python code, and you can see in the screenshot below it is giving me the exact output.

Read How to use Pandas to convert float to int in Python

Method 2: Check for NaN

NaN stands for “Not a Number” and is used to represent undefined or unrepresentable floating-point values. You can check for NaN using the math.isnan() function or the numpy.isnan() function if you are using NumPy.

Using math.isnan()

Here is an example of how to use math.isnan() to check if a float variable is empty.

import math

float_var = float('nan')

if math.isnan(float_var):
    print("The variable is NaN.")
else:
    print("The variable is not NaN.")

If float_var is NaN, the output will be “The variable is NaN.” Otherwise, it will print “The variable is not NaN.”

Using numpy.isnan()

Here is an example of how to use numpy.isnan() to check if a float variable is empty in Python.

import numpy as np

float_var = np.nan

if np.isnan(float_var):
    print("The variable is NaN.")
else:
    print("The variable is not NaN.")

Similar to the math.isnan() method, if float_var is NaN, the output will be “The variable is NaN.” Otherwise, it will print “The variable is not NaN.”

You can see the exact output in the screenshot below after I executed the above Python code using an online Python editor.

check if float variable is empty in python

Read How to convert float to int Python

Method 3: Check for Zero

A float variable with a value of 0.0 can also be considered empty in some contexts. You can check for this using a simple comparison. Here is a simple example of how to check if a float variable is empty using comparison.

float_var = 0.0

if float_var == 0.0:
    print("The variable is zero.")
else:
    print("The variable is not zero.")

If float_var is 0.0, the output will be “The variable is zero.” Otherwise, it will print “The variable is not zero.”

You can see the output in the screenshot below after I executed the above Python code.

How to check if float variable is empty in python

Method 4: Check Multiple Empty Conditions

In some cases, you may want to check for multiple “empty” conditions at once. Here’s how you can combine checks for None, NaN, and 0.0 in Python for a float.

import math

def is_empty_float(value):
    if value is None:
        return True
    if math.isnan(value):
        return True
    if value == 0.0:
        return True
    return False

# Test cases
test_values = [None, float('nan'), 0.0, 1.0, -1.0]

for val in test_values:
    if is_empty_float(val):
        print(f"The variable {val} is considered empty.")
    else:
        print(f"The variable {val} is not considered empty.")

This method checks for None, NaN, and 0.0. For None, NaN, and 0.0, the output will be “The variable <value> is considered empty.” For other values like 1.0 and -1.0, the output will be “The variable <value> is not considered empty.”

Conclusion

In this tutorial, I have explained how to check if a float variable is empty in Python using different methods, with examples. I hope this will help you.