Type Hint

An annotation that specifies the expected type for:

• variable or class attribute (New in Python 3.6, See PEP 526)
• function/method parameter and return type (See PEP 3107)

Use Case

• static type analysis tools
• aid IDEs with code completion and refactoring

Typeshed Stub

pip install mypy

pip install types-xxx

See typeshed on GitHub and mypy on GitHub.

Backward Compability

pip install typing-extensions

See typing-extensions package on PyPI.

typing.get_type_hints()

Type hints of global variables, class attributes, and functions, but not local variables, can be accessed using typing.get_type_hints().

typing.get_type_hints(obj, globalns=None, localns=None, include_extras=False) -> dict

Return a dictionary containing type hints for a function, method, module or class object.

This is often the same as obj.__annotations__. In addition, forward references encoded as string literals are handled by evaluating them in globalns and localns namespaces.

References

• Python - typing module
• PEP 526 - Syntax for Variable Annotations
• PEP 3107 – Function Annotations
• PEP 484 – Type Hints
• PEP 483 – The Theory of Type Hints
• PEP 563 – Postponed Evaluation of Annotations
• mypy Documentation
• GitHub - typeshed
• GitHub - mypy
• PyPI - typing-extensions package