Python Type Hints – How to Handle Optional Imports

Re:Python Type Hints – How to Handle Optional Imports by dragonwriter on Wednesday January 05, 2022 @02:15AM (#29806093)

The thing listed as “A Non-Functioning Alternative” seems to work correctly in both Pylance and mypy, if you add “# type: ignore” at the end of the import line.

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Re:Python Type Hints – How to Handle Optional Imports by adamchainz on Thursday January 06, 2022 @10:36AM (#29824841)

Unfortunately that prevents Mypy from loading the type hints for 'markdown'

    from types import ModuleType

    markdown: ModuleType | None

    try:
        import markdown  # type: ignore [no-redef]
    except ImportError:
        markdown = None

    if markdown is not None:
        reveal_type(markdown.markdown)

Running Mypy:

    example.py:11: note: Revealed type is "Any"

Whereas when correctly imported:

    example.py:3: note: Revealed type is "def (text: builtins.str, *, extensions: Union[typing.Sequence[Union[builtins.str, markdown.extensions.Extension]], None] =, extension_configs: Union[typing.Mapping[builtins.str, typing.Mapping[builtins.str, Any]], None] =, output_format: Union[Literal['xhtml'], Literal['html'], None] =, tab_length: Union[builtins.int, None] =) -> builtins.str"

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