Python __repr__() magic method

Python __repr__() is one of the magic methods that returns a printable representation of an object in Python that can be customized or predefined, i.e. we can also create the string representation of the object according to our needs.

Python __repr__() magic method Syntax

Syntax: object.__repr__()

• object: The object whose printable representation is to be returned.

Return: Simple string representation of the passed object.

Python __repr__() method Example

In this example, we define a GFG class with three instance variables f_name, m_name, and l_name representing the first, middle, and last name of a person, respectively. The __repr__() method is defined to return a string representation of the instance in a format that can be used to recreate the object.

class GFG:
  
    def __init__(self, f_name, m_name, l_name):
        self.f_name = f_name
        self.m_name = m_name
        self.l_name = l_name

    def __repr__(self):
        return f'GFG("{self.f_name}","{self.m_name}","{self.l_name}")'

gfg = GFG("Geeks", "For", "Geeks")
print(repr(gfg))

Output:

GFG("Geeks","For","Geeks")

Difference between __str__() and __repr__() magic method

In this example, we define a GFG class with one instance variable name representing the name of a person. The __str__() method is defined to return a human-readable string representation of the instance, while the __repr__() method is defined to return a string representation of the instance that can be used to recreate the object.

When we create an instance of the GFG class and call __str__() or __repr__() directly on the object, the respective method is called and returns a string that represents the object.

class GFG:

    def __init__(self, name):
        self.name = name

    def __str__(self):
        return f'Name is {self.name}'

    def __repr__(self):
        return f'GFG(name={self.name})'


obj = GFG('GeeksForGeeks')

print(obj.__str__())
print(obj.__repr__())

Output:

Name is GeeksForGeeks
GFG(name=GeeksForGeeks)

You can also read str() vs repr() in Python.

__str__() and __repr__() Examples Using a Built-In Class

In this example, we define a subclass of tuple called MyTuple that overrides the __str__() and __repr__() methods. When we call Python str() or Python repr() on an instance of MyTuple, the custom __str__() and __repr__() methods are called, respectively.

class MyTuple(tuple):
    def __str__(self):
        return f"MyTuple({super().__str__()})"

    def __repr__(self):
        return f"MyTuple({super().__repr__()})"
mt = MyTuple((1,2,3))
print(mt.__repr__())
print(mt.__str__())

Output:

MyTuple((1, 2, 3))
MyTuple(MyTuple((1, 2, 3)))

__str__() and __repr__() Examples Using a New Class

In this example, we define a Book class with three instance variables title, author, and pages representing the title, author, and number of pages of a book, respectively. The __str__() method is defined to return a string representation of the instance in a human-readable format, while the __repr__() method is defined to return a string representation of the instance that can be used to recreate the object.

When we create an instance of the Book class and call str() on it, the __str__() method is called and returns a human-readable string that represents the object. When we call repr() on it, the __repr__() method is called and returns a string that represents the object in a way that it can be recreated.

class Book:
    def __init__(self, title, author, pages):
        self.title = title
        self.author = author
        self.pages = pages

    def __str__(self):
        return f"{self.title} by {self.author}, {self.pages} pages"

    def __repr__(self):
        return f"Book('{self.title}', '{self.author}', {self.pages})"

book1 = Book("The Hitchhiker's Guide to the Galaxy", "Douglas Adams", 224)

print("Using str(): ", str(book1))
print("Using repr(): ", repr(book1))

Output:

Using str():  The Hitchhiker's Guide to the Galaxy by Douglas Adams, 224 pages
Using repr():  Book('The Hitchhiker's Guide to the Galaxy', 'Douglas Adams', 224)

Practical usage of __repr__() magic method

This code creates a Color class with an __init__() method that takes a suffix parameter and sets an instance variable self. suffix to that value. It also sets another instance variable self. title to a string that includes the suffix. Finally, it defines an __repr__() method that returns a string representation of the object.

class Color:
    def __init__(self, suffix):
        self.suffix = suffix
        self.title = f"Golden {suffix}"

    def __repr__(self):
        return f"Color('{self.suffix}')"


c1 = Color("Yellow")
# create another object with same params as c1
# using eval() on repr()
c2 = eval(repr(c1))

print("c1.title:", c1.title)
print("c2.title:", c2.title)

Output:

c1.title: Golden Yellow
c2.title: Golden Yellow