Exploring Protocols in Python: Understanding & Creating Custom Protocols

This is a preview of the video course, "Exploring Protocols in Python". In Python, a protocol specifies the methods and attributes that a class must implement to be considered of a given type. Protocols are important in Python’s type hint system, which allows for static type checking through external tools, such as mypy, Pyright, and Pyre.

Before there were protocols, these tools could only check for nominal subtyping based on inheritance. There was no way to check for structural subtyping, which relies on the internal structure of classes. This limitation affected Python’s duck typing system, which allows you to use objects without considering their nominal types. Protocols overcome this limitation, making static duck typing possible.

This is a portion of the complete course, which you can find here:
https://realpython.com/courses/explor...

The rest of the course covers:
Using Custom Protocols in Python
Building Generic Protocols
Exploring Possible Protocol Members
Creating Subprotocols