{"id":1092,"date":"2020-11-13T03:34:27","date_gmt":"2020-11-13T03:34:27","guid":{"rendered":"https:\/\/www.pythontutorial.net\/?page_id=1092"},"modified":"2025-03-31T08:56:31","modified_gmt":"2025-03-31T08:56:31","slug":"python-__repr__","status":"publish","type":"page","link":"https:\/\/www.pythontutorial.net\/python-oop\/python-__repr__\/","title":{"rendered":"Python __repr__"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you’ll learn how to use the Python __repr__<\/code> dunder method and the difference between the __repr__<\/code> and __str__<\/code> methods.<\/p>\n\n\n\n

Introduction to the Python __repr__ magic method #<\/a><\/h2>\n\n\n\n

The __repr__<\/code> dunder method defines behavior when you pass an instance of a class<\/a> to the repr()<\/code>.<\/p>\n\n\n\n

The __repr__<\/code> method returns the string representation of an object. Typically, the __repr__()<\/code> returns a string that can be executed and yield the same value as the object. <\/p>\n\n\n\n

In other words, if you pass the returned string of the object_name.__repr__()<\/code> method to the eval()<\/code> function, you’ll get the same value as the object_name<\/code>. Let’s take a look at an example.<\/p>\n\n\n\n

First, define the Person<\/code> class with three instance attributes first_name<\/code>, last_name<\/code>, and age<\/code>:<\/p>\n\n\n

class<\/span> Person<\/span>:<\/span>\n    def<\/span> __init__<\/span>(self, first_name, last_name, age)<\/span>:<\/span>\n        self.first_name = first_name\n        self.last_name = last_name\n        self.age = age<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Second, create a new instance of the Person<\/code> class and display its string representation:<\/p>\n\n\n
person = Person('John'<\/span>, 'Doe'<\/span>, 25<\/span>)\nprint(repr(person))<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
<__main__.Person<\/span> object<\/span> at<\/span> 0x000001F51B3313A0<\/span>><\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
By default, the output contains the memory address of the person<\/code> object. To customize the string representation of the object, you can implement the __repr__<\/code> method like this:<\/p>\n\n\n
class<\/span> Person<\/span>:<\/span>\n    def<\/span> __init__<\/span>(self, first_name, last_name, age)<\/span>:<\/span>\n        self.first_name = first_name\n        self.last_name = last_name\n        self.age = age\n\n    def<\/span> __repr__<\/span>(self)<\/span>:<\/span>\n        return<\/span> f'Person(\"{self.first_name}<\/span>\",\"{self.last_name}<\/span>\",{self.age}<\/span>)'<\/span><\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
When you pass an instance of the Person<\/code> class to the repr()<\/code>, Python will call the __repr__<\/code> method automatically. For example:<\/p>\n\n\n
person = Person(\"John\"<\/span>, \"Doe\"<\/span>, 25<\/span>)\nprint(repr(person))<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
Person(\"John\"<\/span>,\"Doe\"<\/span>,25<\/span>)<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
If you execute the return string Person(\"John\",\"Doe\",25)<\/code>, it’ll return the person<\/code> object.<\/p>\n\n\n\n
For example:<\/p>\n\n\n
person = Person('John'<\/span>, 'Doe'<\/span>, 25<\/span>)\nprint(person)<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
Person(\"John\"<\/span>,\"Doe\"<\/span>,25<\/span>)<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
If a class implements the __str__<\/code> method, Python will call the __str__<\/code> method when you pass an instance of the class to the str()<\/code>. For example:<\/p>\n\n\n
class<\/span> Person<\/span>:<\/span>\n    def<\/span> __init__<\/span>(self, first_name, last_name, age)<\/span>:<\/span>\n        self.first_name = first_name\n        self.last_name = last_name\n        self.age = age\n\n    def<\/span> __repr__<\/span>(self)<\/span>:<\/span>\n        return<\/span> f'Person(\"{self.first_name}<\/span>\",\"{self.last_name}<\/span>\",{self.age}<\/span>)'<\/span>\n\n    def<\/span> __str__<\/span>(self)<\/span>:<\/span>\n        return<\/span> f'({self.first_name}<\/span>,{self.last_name}<\/span>,{self.age}<\/span>)'<\/span>\n\n\nperson = Person('John'<\/span>, 'Doe'<\/span>, 25<\/span>)\n# use str()<\/span>\nprint(person)\n\n# use repr()<\/span>\nprint(repr(person))\n<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
(John,Doe,25<\/span>)\nPerson(\"John\"<\/span>,\"Doe\"<\/span>,25<\/span>)<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
__str__ vs __repr__ #<\/a><\/h2>\n\n\n\n
The main difference between __str__<\/code> and __repr__<\/code> method is intended audiences.<\/p>\n\n\n\n
The __str__<\/code> method returns a string representation of an object that is human-readable while the __repr__<\/code> method returns a string representation of an object that is machine-readable.<\/p>\n\n\n\n
Summary #<\/a><\/h2>\n\n\n\n
Try it<\/a><\/p>\n\n\n\n
When a class doesn’t implement the __str__<\/a><\/code> method and you pass an instance of that class to the str()<\/code>, Python returns the result of the __repr__<\/code> method because internally the __str__<\/code> method calls the __repr__<\/code> method:<\/p>\n\n\n\n