Tutorial document

Thoughts on the tutorial document.

Basic Topics

• Set up a basic venv with a pinned mypy version. (For compatibility reasons.) Should add a note about using a current version in production.
• Annotating variables.
• Annotating functions and methods.
• Unions, using | None
• Any
• cast() and # type: ignore
• Using generics, variance
• Built-in collections
• Type aliases
• int/float
• NoReturn (not strictly necessary, but a fairly easy topic)
• Installing third-party stubs

Advanced Topics

The are fairly complicated topics, but basically required when typing a non-trivial code base:

• Callable
• Writing generics
• Protocols
• type[...]
• typing.TYPE_CHECKING and circular imports
• TypeVar and AnyStr
• overloads
• Literal

What not to include

• # type annotations (except # type: ignore)

The following topics could arguably be included, but for simplicity's sake, I'd suggest to skip them in this basic tutorial:

• NewType
• ClassVar
• Final
• Annotated
• NamedTuple
• TypedDict

Other Thoughts

• We can use a newer version of Python (e.g. 3.8+) for simplicity and add a note that not all features are available in older Python versions.
• We should probably just use from __future__ import annotations and skip the whole forward references/quoting types problem.

Nell’issue non sono indicati alcun file del tutorial, punto di ingresso o test. Inizia individuando la documentazione esistente del tutorial e confrontala con gli elenchi proposti degli argomenti di base e avanzati. Il lavoro è considerato completato quando sono stati concordati l’ambito del tutorial, le indicazioni sulla versione di Python, gli argomenti di typing inclusi e le esclusioni, e queste decisioni sono state documentate.