Understand Python Null and None Keyword

By Digamber Rawat Last updated on
We are going to understand today the Python Null and None Keyword. The null or none is data a type in Python, which refers to no value defined. If you have experience in other programming languages, then you must be aware of the null keyword. The null keyword is almost used in many other programming languages such as C++, C#, Java, and JavaScript.

In the below example, I will show you how to assign None Type object using the None keyword.

myObj = None

print(type(myObj))

# output = <class 'NoneType'>

As you can see, I have declared the myObj and set NoneType value to the object. When I am printing the result, it is returning the class NoneType

Is None or Null in Python Similar in Other Programming Languages?

There are lots of programmers who switched to Python from other programming backgrounds. They must have used the Null keyword to define no value. Check out below in example, how we define null in PHP and Java?

Define null in Java

customVariable = null;

Define null in PHP

<?php
  $customVariable = NULL;       
?>

When Should I use NoneType Object in Python?

In almost every programming languages using null or none keyword with an if statement is standard practice. However, Python doesn’t offer null keyword support. Instead, we can use None data type to represent no value, and it is an object type in Python.

Python null or None explanation:

  • If the function doesn’t return anything that means its null or None in Python.
  • It returns the NoneType object when the key in the collection is not available.
  • To verify the returned value of a function, we use NoneType object in Python.

How to Identify if the Variable is None in Python?

We can quickly identify if the variable is None in Python. You can use the == operator, or you can find the NoneType by using the is keyword.

Checking None Type with is Keyword

none_var = None
not_none_var = 'Hello John!'
 
if none_var is None:
    print('none_var is None')
else:
    print('none_var is not None')
 
if not_none_var is None:
    print('not_none_var is None')
else:
    print('not_none_var is not None')

# output = none_var is None
# output = not_none_var is not None

Checking None Type with is Keyword

none_var = None
not_none_var = 'Hello John!'

if none_var == None:
    print('none_var is None')
else:
    print('none_var is not None')
 
if not_none_var == None:
    print('not_none_var is None')
else:
    print('not_none_var is not None')

# output = none_var is None
# output = not_none_var is not None

In the above example, we tested null and none in Python. We declared 2 variable to check null or NoneType result using is the and == operator. In the first variable, we injected None value type. and in another variable, we injected a single string value. Then we put them through the condition, and we got the return type none for the 1st variable and for the 2nd variable not none result returned.

Finally, we’ve completed this Python Null and None Keyword tutorials with examples. If you want to explore more in Python i would suggest visit Python official website to get more ideas about the power and flexibility of Python.

Digamber Rawat
Digamber Rawat

Full stack developer with a passion for UI/UX design. I create beautiful and useful digital products to solve people’s problem and make their life easy.

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