In this tutorial, we’re going to focus on how to test if something is null in Python – a useful concept while writing Python scripts where you may encounter null (None) values.

Python uses the keyword None to define null objects and variables. Our objective here is to identify these None values and treat them correctly in our program. Let’s get started.

Step 1: Understanding the concept of None

In Python, the None keyword is used to define a null value or no value at all. None is not the same as 0, False, or an empty string. None is a data type of its own (NoneType) and only None can be None.

Step 2: Using the equality operator (==)

You can check if a variable is None using the == operator. This is an easy and straightforward method to check for None.

The above code will print ‘x is None’ since variable x is indeed None. However, using ‘==’ is not a recommended way. Well, it doesn’t cause any errors but it’s not pythonic.

Step 3: The Pythonic way – ‘is’ keyword

The more Pythonic way of checking if something is none is by using the is keyword. Python’s “is” keyword is used to test object identity while the ‘==’ operator is used to test the equality of two variables.

This ‘is’ keyword checks if both the variables point to the same memory location while == checks if the values for the variables are the same. So, when comparing objects to None, always use the is operator.

Here’s the full code used in this tutorial:

Output

x is None
x is None

Conclusion

To conclude, checking if a variable is None is a very common operation in Python. Therefore, understanding the methods and the differences between them is very important for a Python programmer. Remember, the recommended Pythonic way to compare a variable to None is with the is operator, not the == operator.