__name__ is the special variable in python that provides the name of the current module where it is used. Note that to display the class name you have to create the object for that lass and display its name using class.name. Check out the below example for a better understanding of these methods.
__class__ is just a reference to the class object, just like class_obj = Foo would create a reference to a class. Calling the class object produces a new instance, whatever reference you used to get to it. That's because type is its own type.
In Short: It Allows You to Execute Code When the File Runs as a Script, but Not When It's Imported as a Module. For most practical purposes, you can think of the conditional block that you open with if __name__ == "__main__" as a way to store code that should only run when your file is executed as a script.
The __name__ attribute returns the name of the module. By default, the name of the file (excluding the extension . py) is the value of __name__attribute. In the same way, it gives the name of your custom module e.g. calc module will return 'calc'.
A module can define functions, classes, and variables. So when the interpreter runs a module, the __name__ variable will be set as __main__ if the module that is being run is the main program. But if the code is importing the module from another module, then the __name__ variable will be set to that module's name.
__str__ : the string representation method of an object, which is called when you use the str function to convert that object to a string. __class__ : an attribute which stores the the class (or type) of an object – this is what is returned when you use the type function on the object.
The __init__ method is the Python equivalent of the C++ constructor in an object-oriented approach. The __init__ function is called every time an object is created from a class. The __init__ method lets the class initialize the object's attributes and serves no other purpose. It is only used within classes.
The special method . __repr__() returns the official string representation, which is aimed at programmers as they develop and maintain a program. The special method . __str__() returns the informal string representation, a friendlier format for the program's user.
__str__ is a special method, like __init__ , that is supposed to return a string representation of an object. When I write a new class, I almost always start by writing __init__ , which makes it easier to instantiate objects, and __str__ , which is useful for debugging.
Single leading underscores is a convention. there is no difference from the interpreter's point of view if whether names starts with a single underscore or not. Double leading and trailing underscores are used for built-in methods, such as __init__ , __bool__ , etc.
Differences between __new__ and __init__
__new__ is a static method, while __init__ is an instance method. __new__ is responsible for creating and returning a new instance, while __init__ is responsible for initializing the attributes of the newly created object.
The python __init__ method is declared within a class and is used to initialize the attributes of an object as soon as the object is formed. While giving the definition for an __init__(self) method, a default parameter, named 'self' is always passed in its argument. This self represents the object of the class itself.
The Python interpreter modifies the variable name with ___. So Multiple times It uses as a Private member because another class can not access that variable directly. The main purpose for __ is to use variable /method in class only If you want to use it outside of the class you can make it public.
What is __init__ in Python? The Default __init__ Constructor in C++ and Java. Constructors are used to initializing the object's state. The task of constructors is to initialize(assign values) to the data members of the class when an object of the class is created.
__attribute__ format
This __attribute__ allows assigning printf-like or scanf-like characteristics to the declared function, and this enables the compiler to check the format string against the parameters provided throughout the code. This is exceptionally helpful in tracking down hard-to-find bugs.
Class Attributes are the attributes that belong to the class itself rather than a particular object. Usually, we use class attributes to define the attributes that have a common value among all the objects inside the class. Class Methods are the methods that have access to the class attributes.
Unlike instance attributes, which are independent for each instance of the class, class attributes are the same for every instance.
__call__() method turns instances into callable objects. As you already learned, Python automatically calls this method whenever you call a concrete instance of a given class. To illustrate the differences between both methods, consider the following example class: >>> class Demo: ... def __init__(self, attr): ...
Optionally, descriptors can have a __set_name__() method. This is only used in cases where a descriptor needs to know either the class where it was created or the name of class variable it was assigned to. (This method, if present, is called even if the class is not a descriptor.)
self. __class__ is a reference to the type of the current instance. For instances of abstract1 , that'd be the abstract1 class itself, which is what you don't want with an abstract class.
Hence, we can create any number of objects, and every object can have its values for the attributes. This is the functionality of the __init__ method in object-oriented programming in Python. Let us see one more example: We can take the values as inputs from the user and then pass them as attributes to an object.
In Python, there is no existence of Private methods that cannot be accessed except inside a class. However, to define a private method prefix the member name with the double underscore “__”. Note: The __init__ method is a constructor and runs as soon as an object of a class is instantiated.
Starting with Python 3.3, Implicit Namespace Packages were introduced. These allow for the creation of a package without any __init__.py file. Of course, it can still be present if package initialization is needed. But it is no longer required.
__new__() is a static method (special-cased so you need not declare it as such) that takes the class of which an instance was requested as its first argument. As shown above, when __new__() is called directly, the class has to be passed explicitly as the first argument.
A class can have one constructor __init__ which can perform any action when the instance of the class is created. This constructor can be made to different functions that carry out different actions based on the arguments passed.