Method parse

pex/pep_723.py:235–297

(
        cls,
        script,  # type: Text
        source=_UNSPECIFIED_SOURCE,  # type: str
    )

class ScriptMetadata(object):
    @classmethod
    def parse(
        cls,
        script,  # type: Text
        source=_UNSPECIFIED_SOURCE,  # type: str
    ):
        # type: (...) -> ScriptMetadata

        # The spec this code follows was defined in PEP-723: https://peps.python.org/pep-0723/
        # and now lives here:
        # https://packaging.python.org/specifications/inline-script-metadata#inline-script-metadata
        script_metadata_block = parse_metadata_blocks(script, source=source).get("script")
        if not script_metadata_block:
            return cls()
        script_metadata = script_metadata_block.parse_metadata()

        raw_dependencies = script_metadata.get("dependencies", [])
        if not isinstance(raw_dependencies, list):
            raise script_metadata_block.create_metadata_error(
                "contains an invalid `dependencies` value of type `{type}`\n"
                "Expected a list of dependency specifier strings".format(
                    type=type(raw_dependencies).__name__
                )
            )

        invalid_dependencies = []  # type: List[str]
        dependencies = []  # type: List[ParsedRequirement]
        for index, req in enumerate(raw_dependencies):
            try:
                dependencies.append(
                    as_parsed_requirement(Requirement.parse(req), line=LogicalLine.from_str(req))
                )
            except RequirementParseError as e:
                invalid_dependencies.append(
                    "+ dependencies[{index}] {req!r}: {err}".format(index=index, req=req, err=e)
                )
        if invalid_dependencies:
            raise script_metadata_block.create_metadata_error(
                "contains a `dependencies` list with {count} invalid dependency {specifiers}:\n"
                "{invalid_dependencies}".format(
                    count=len(invalid_dependencies),
                    specifiers=pluralize(invalid_dependencies, "specifier"),
                    invalid_dependencies="\n".join(invalid_dependencies),
                )
            )

        raw_requires_python = script_metadata.get("requires-python", "")
        if not isinstance(raw_requires_python, string):
            raise script_metadata_block.create_metadata_error(
                "contains an invalid `requires-python` value of type `{type}`\n"
                "Expected a version specifier string".format(
                    type=type(raw_requires_python).__name__
                )
            )
        try:
            requires_python = SpecifierSet(raw_requires_python)
        except InvalidSpecifier as e:
            raise script_metadata_block.create_metadata_error(
                "contains an invalid `requires-python` value {value!r}: {err}".format(