In the program output, we can represent Python strings in two ways. Python supports both informal and formal string representations. When we run the Python program to print the string, we get an informal representation of it in the output.<\/p>\n\n\n\n
The In this article, we’ll discuss these dunder methods named The The Overall, the We can implement these methods within the Python class to see them in action. Let’s look at the following example.<\/p>\n\n\n\n We created the Then we implemented the When we ran the above code, we got the object’s location in the processor’s memory as a hexadecimal number.<\/p>\n\n\n\n This happened because we didn’t implement the In the following code, we implemented the custom Output<\/strong><\/p>\n\n\n\n We got the string defined in the class’s What if we only implement the<\/strong> We’ve added the Output<\/strong><\/p>\n\n\n\n As previously discussed, if So far, we’ve used user-defined classes to implement the We’ll see what happens when we call the We used the Output<\/strong><\/p>\n\n\n\n The output shows that the The The methods The For pre-defined or built-in Python classes, we don’t need to define the The address of the object is returned by the default implementation of the \ud83c\udfc6Other articles you might be interested in if you liked this one<\/strong><\/p>\n\n\n\n \u2705How Python sort() and sorted() methods are different and how they are used<\/a>?<\/p>\n\n\n\n \u2705How to move and locate the file pointer using seek() and tell() in Python<\/a>?<\/p>\n\n\n\n \u2705All about Python’s ABC – What is it and how to use it<\/a>?<\/p>\n\n\n\n \u2705Generate and manipulate the temporary files using tempfile in Python<\/a>.<\/p>\n\n\n\n \u2705How to use the super() function in Python classes<\/a>?<\/p>\n\n\n\n \u2705Get started with FastAPI – A detailed guide<\/a>.<\/p>\n\n\n\n__str__<\/code> method in Python is responsible for the informal representation of the object, which we can change to the formal representation by using the __repr__<\/code> method.<\/p>\n\n\n\n__str__<\/code> and __repr__<\/code> and how they are used for changing the representation of the string.<\/p>\n\n\n\n<\/a>__str__() and __repr__() method<\/h2>\n\n\n\n
__str__()<\/code> method returns the object’s easily-readable or informal string representation. Python calls the __str__()<\/code> method internally when we call functions like str()<\/code> and print()<\/code>.<\/p>\n\n\n\n__repr__()<\/code> method, unlike the __str__()<\/code> method, returns a more informative or formal string representation of the object. When the __str__()<\/code> method for the class is not defined, the object calls the __repr__()<\/code> method.<\/p>\n\n\n\n__str__()<\/code> method is meant for users, whereas the __repr__()<\/code> method is meant for developers and can be more useful when debugging.<\/p>\n\n\n\n<\/a>Default implementation<\/h3>\n\n\n\n
# Python class is created\nclass Product:\n def __init__(self, name, category):\n self.name = name\n self.category = category\n\n# Instantiated the class\ndata = Product('Ford', 'Car')\n\n# Implemented the __str__() method\nprint(data.__str__())\nprint(data.__repr__())\nprint(data)<\/pre><\/div>\n\n\n\nProduct<\/code> class and defined the __init__<\/code> function that takes name<\/code> and category<\/code>. Then we instantiated the class Product<\/code> with the necessary arguments.<\/p>\n\n\n\n__str__()<\/code> and __repr__()<\/code> methods to the object of the class Product<\/code>.<\/p>\n\n\n\n<__main__.Product object at 0x000002157F10C370>\n<__main__.Product object at 0x000002157F10C370>\n<__main__.Product object at 0x000002157F10C370><\/pre><\/div>\n\n\n\n
__str__()<\/code> and __repr__()<\/code> methods within our class Product<\/code>. Thus, calling the __str__()<\/code> method calls the default __repr__()<\/code> method and shows the same output.<\/p>\n\n\n\n<\/a>Custom __str__() method<\/h3>\n\n\n\n
__str__()<\/code> method that returns a string with some information and then we executed the code to see what would be the output.<\/p>\n\n\n\n# Python class is created\nclass Product:\n def __init__(self, name, category):\n self.name = name\n self.category = category\n\n # Creating __str__() function\n def __str__(self):\n return f'The {self.name} belongs to category {self.category}.'\n\n# Instantiated the class\ndata = Product('Ford', 'Car')\n\n# Implemented the __str__() method\nprint(data.__str__())\nprint(data.__repr__())\nprint(data)<\/pre><\/div>\n\n\n\nThe Ford belongs to category Car.\n<__main__.Product object at 0x00000156D7E5C370>\nThe Ford belongs to category Car.<\/pre><\/div>\n\n\n\n
__str__()<\/code> method when we called the __str__()<\/code> and print()<\/code> methods on the object data<\/code>, but not when we called the __repr__()<\/code> method on the object data<\/code>.<\/p>\n\n\n\n<\/a>Only __repr__() method<\/h3>\n\n\n\n
__repr__()<\/code> method within the class<\/strong> Product<\/code>?<\/strong><\/p>\n\n\n\n__repr__()<\/code> method to the Product<\/code> class, which returns a string containing the product name and category.<\/p>\n\n\n\n# Python class is created\nclass Product:\n def __init__(self, name, category):\n self.name = name\n self.category = category\n\n # Creating __repr__() function\n def __repr__(self):\n return f'Product: {self.name} - Category: {self.category}.'\n\n# Instantiated the class\ndata = Product('Ford', 'Car')\n\n# Called the __str__() method\nprint(data.__str__())\n# Called the __repr__() method\nprint(data.__repr__())\nprint(data)\n# Called the str() function\nprint(str(data))<\/pre><\/div>\n\n\n\nProduct: Ford - Category: Car.\nProduct: Ford - Category: Car.\nProduct: Ford - Category: Car.\nProduct: Ford - Category: Car.<\/pre><\/div>\n\n\n\n
__str__()<\/code> is not defined for the class, the object will invoke the class’s __repr__()<\/code> method. That’s why we got the string even though we called __str__()<\/code>, print()<\/code>, and str()<\/code> on the object data<\/code>.<\/p>\n\n\n\n<\/a>Calling __str__() and __repr__() on built-in class<\/h2>\n\n\n\n
__str__()<\/code> and __repr__()<\/code> methods. Now we’ll look at how these methods are implemented in Python’s built-in classes.<\/p>\n\n\n\n__str__()<\/code> and __repr__()<\/code> methods on the Python built-in datetime<\/code> module’s classes.<\/p>\n\n\n\nimport datetime\n\ntoday = datetime.datetime.today()\n\nprint(f'Normal: {today}')\nprint('-'*20)\nprint(f'__str__ method: {today.__str__()}')\nprint(f'str() method: {str(today)}')\nprint('-'*20)\nprint(f'__repr__ method: {today.__repr__()}')\nprint(f'repr() method: {repr(today)}')<\/pre><\/div>\n\n\n\n__str__()<\/code>, str()<\/code>, __repr__()<\/code>, and repr()<\/code> methods on the variable today<\/code> to print the current date and time.<\/p>\n\n\n\nNormal: 2023-04-12 18:16:27.991308\n--------------------\n__str__ method: 2023-04-12 18:16:27.991308\nstr() method: 2023-04-12 18:16:27.991308\n--------------------\n__repr__ method: datetime.datetime(2023, 4, 12, 18, 16, 27, 991308)\nrepr() method: datetime.datetime(2023, 4, 12, 18, 16, 27, 991308)<\/pre><\/div>\n\n\n\n
__str__()<\/code> and str()<\/code> methods returned an informal or easily readable string representation, whereas the __repr__()<\/code> and repr()<\/code> methods returned a more informative or formal string representation.<\/p>\n\n\n\n__str__()<\/code> method is implemented by default in pre-defined or built-in Python classes, so we don’t need to define them explicitly.<\/p>\n\n\n\n<\/a>Conclusion<\/h2>\n\n\n\n
__str__()<\/code> and __repr__()<\/code> are used to represent objects in string format. The __str__()<\/code> method returns a human-readable or informal string representation of the object, whereas the __repr__()<\/code> method returns a more informative or formal string representation of the object.<\/p>\n\n\n\n__str__()<\/code> method is for users, whereas the __repr__()<\/code> method is for developers because it is more useful when debugging.<\/p>\n\n\n\n__str__()<\/code> method explicitly because it is implemented by default, whereas for user-defined Python classes, we must define a custom __str__()<\/code> method to get the string representation of the object; otherwise, it will return the object’s memory address.<\/p>\n\n\n\n__str__()<\/code> and __repr__()<\/code> functions on the object of the user-defined Python class. To return the string representation of the object, the custom __str__()<\/code> and __repr__()<\/code> methods must be defined within the class, and if __str__()<\/code> is not defined, the object will call the __repr__()<\/code> method.<\/p>\n\n\n\n
\n\n\n\n