Why Does Python Require the Explicit \'self\' Argument in Methods?

Why Python Methods Require the Explicit "self" Argument

Unlike in programming languages like C#, Python methods require the explicit inclusion of the "self" argument. This intentional language design decision has several underlying reasons:

Explicitly Defining Object Ownership

The "self" argument makes it clear that the method belongs to the object it is called on. This unambiguous ownership ensures clarity in code organization and reduces confusion over which object the method is operating upon.

Access to Instance Variables and Methods

By having the "self" argument passed as the first parameter, methods can access instance variables and other methods of the object they belong to. These properties and methods are represented by self.property and self.method, respectively.

Convenience for Instantiation and Calling

The "self" argument provides a convenient way to instantiate and call methods on objects. For example, the following code demonstrates the creation and invocation of a class method:

<code class="python">class MyClass:
    def __init__(self):
        self.x = 10
        self.y = 20

    def calculate(self):
        return self.x + self.y

obj = MyClass()
result = obj.calculate()</code>

Exposed Implementation Structures

The existence of the "self" argument allows for the exposure of internal structures such as self.__class__, self.__dict__, and others. This facilitates introspection and allows for advanced programming techniques like metaclasses and dynamic language features.

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