{"id":2348,"date":"2021-02-27T07:04:27","date_gmt":"2021-02-27T07:04:27","guid":{"rendered":"https:\/\/www.pythontutorial.net\/?page_id=2348"},"modified":"2025-03-27T13:31:17","modified_gmt":"2025-03-27T13:31:17","slug":"python-none","status":"publish","type":"page","link":"https:\/\/www.pythontutorial.net\/advanced-python\/python-none\/","title":{"rendered":"Python None"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you’ll learn about Python None<\/code> and how to use it properly in your code.<\/p>\n\n\n\n

Introduction to the Python None value #<\/a><\/h2>\n\n\n\n

In Python, None<\/code> is a special object of the NoneType<\/code> class<\/a>. To use the None<\/code> value, you specify the None<\/code> as follows:<\/p>\n\n\n

None<\/span><\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
If you use the type()<\/code> function to check the type of the None<\/code> value, you’ll get NoneType<\/code> class:<\/p>\n\n\n
print(type(None<\/span>))<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
<class<\/span> 'NoneType<\/span>'><\/span><\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
The None<\/code> is a singleton object of the NoneType<\/code> class. It means that Python creates one and only one<\/strong> None<\/code> object at runtime.<\/p>\n\n\n\n
Therefore, if you use the equality (==<\/code>) or is<\/code> operator to compare None<\/code> with None<\/code>, you’ll get the result of True<\/code>:<\/p>\n\n\n
print(None<\/span> == None<\/span>)\nprint(None<\/span> is<\/span> None<\/span>)<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
True<\/span>\nTrue<\/span><\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
The reason is that the user-defined objects may change the equality operator’s behavior by overriding the __eq__()<\/code> method. For example:<\/p>\n\n\n
class<\/span> Apple<\/span>:<\/span>\n    def<\/span> __eq__<\/span>(self, other)<\/span>:<\/span>\n        return<\/span> True<\/span>\n\n\napple = Apple()\nprint(apple == None<\/span>)<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
True<\/span><\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Note that you cannot override the is<\/code> operator behavior like you do with the equality operator (==<\/code>).<\/p>\n\n\n\n
It’s also important to note that the None object has the following features:<\/p>\n\n\n\n
Try it<\/a><\/p>\n\n\n\n
It’s a good practice to use the is<\/a><\/code> or is not<\/code> operator to compare a value with None<\/code>. <\/p>\n\n\n\n
Try it<\/a><\/p>\n\n\n\n
Try it<\/a><\/p>\n\n\n\n