Duck Typing and Polymorphism in Python

This article introduces duck typing and polymorphism as fundamental concepts in object-oriented programming, particularly in Python's dynamic typing environment. Duck typing is explained through the principle that if an object behaves like a certain type (has the same methods and properties), it can be treated as that type without explicit type checking.

The article provides practical examples of duck typing, including a function that accepts any object with a __len__ method, demonstrating how lists, strings, dictionaries, and custom objects can all be processed uniformly. Code examples show how Python's flexibility allows different data types to be handled by the same function as long as they support the required operations.

Polymorphism is then explained as the ability of objects to take multiple forms, where subclasses can override or extend parent class methods. The article demonstrates this through inheritance examples, showing how a parent class reference can point to child class objects that implement their own versions of methods.

The article combines both concepts by showing how they complement each other in practice. Examples include flying objects where different classes implement the same interface, iterators that can be processed uniformly, and file handling where different objects support the same read operation.

Advanced examples cover sorting objects that support comparison operations, calculating areas of different shapes through polymorphic methods, and handling various file-like objects through duck typing. The article emphasizes how these concepts enable writing flexible, reusable code that can handle diverse object types based on their capabilities rather than their explicit types.