[realpython-bot]

Maintenance sync for the tutorial Python Protocols: Leveraging Structural Subtyping.

What changed and why

• adder_v5.py and adder_v6.py: moved the PEP 695 type parameter from the .add() method to the Adder protocol class (class Adder[T: int | float | str](Protocol)). With the parameter on the method, the method itself is generic, so mypy rejects IntAdder, FloatAdder, and StrAdder because their non-generic .add() methods don't satisfy a generic method. The class-level form is the PEP 695 equivalent of adder_v4.py. The tutorial's Python 3.12 syntax block gets the same fix in this update.

Article draft: https://realpython.com/pbjt/blog/post/2561/change/
Maintenance card: https://trello.com/c/hUQ0iXBQ

Verification

• mypy==2.4.0 (the tutorial's new pin) on adder_v5.py and adder_v6.py: 2 and 3 errors before, Success: no issues found after.
• Every script in the folder executed on Python 3.12 and 3.14 with mypy==2.4.0 installed: all exit 0.
• uvx ruff@0.14.1 format --check python-protocol and uvx ruff@0.14.1 check python-protocol: clean.

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