How Does the = Operator Work in Python?

Understanding the = Operator in Python

The = operator in Python is a shorthand notation that simplifies code by combining assignment and arithmetic operations. However, it's important to delve into its underlying mechanism to fully grasp its functionality.

Python's = operator is essentially a syntactic sugar representing the special method iadd__. When applied to a class, this method enables the class to define custom behavior for the = operator. In other words, when an object of that class is the subject of = operation, the __iadd method of that class is invoked.

To illustrate, let's create a custom class Adder with an iadd method:

class Adder(object):
    def __init__(self, num=0):
        self.num = num

    def __iadd__(self, other):
        print('in __iadd__', other)
        self.num = self.num + other
        return self.num

When you initialize an Adder object and use the = operator, the iadd method is called:

a = Adder(2)
a += 3

This output demonstrates the call to __iadd__:

in __iadd__ 3

The flexibility of iadd allows it to handle various operations. The list object, for instance, uses it to append elements using iterable objects through the extend method.

Understanding shorthand tools in Python is crucial for efficient coding. Here are some useful links to definitions of other such operators:

• [List of all shorthand operators in Python](https://www.w3resource.com/python-exercises/python-conditional-statement-exercises.php)
• [Detailed explanation of = operator](https://realpython.com/python-operators/)

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