codekingpro/portable-devtools

1import functools2import warnings3import re4import textwrap5import email.message6 7from ._text import FoldedCase8from ._compat import pypy_partial9 10 11# Do not remove prior to 2024-01-01 or Python 3.1412_warn = functools.partial(13    warnings.warn,14    "Implicit None on return values is deprecated and will raise KeyErrors.",15    DeprecationWarning,16    stacklevel=pypy_partial(2),17)18 19 20class Message(email.message.Message):21    multiple_use_keys = set(22        map(23            FoldedCase,24            [25                'Classifier',26                'Obsoletes-Dist',27                'Platform',28                'Project-URL',29                'Provides-Dist',30                'Provides-Extra',31                'Requires-Dist',32                'Requires-External',33                'Supported-Platform',34                'Dynamic',35            ],36        )37    )38    """39    Keys that may be indicated multiple times per PEP 566.40    """41 42    def __new__(cls, orig: email.message.Message):43        res = super().__new__(cls)44        vars(res).update(vars(orig))45        return res46 47    def __init__(self, *args, **kwargs):48        self._headers = self._repair_headers()49 50    # suppress spurious error from mypy51    def __iter__(self):52        return super().__iter__()53 54    def __getitem__(self, item):55        """56        Warn users that a ``KeyError`` can be expected when a57        missing key is supplied. Ref python/importlib_metadata#371.58        """59        res = super().__getitem__(item)60        if res is None:61            _warn()62        return res63 64    def _repair_headers(self):65        def redent(value):66            "Correct for RFC822 indentation"67            if not value or '\n' not in value:68                return value69            return textwrap.dedent(' ' * 8 + value)70 71        headers = [(key, redent(value)) for key, value in vars(self)['_headers']]72        if self._payload:73            headers.append(('Description', self.get_payload()))74        return headers75 76    @property77    def json(self):78        """79        Convert PackageMetadata to a JSON-compatible format80        per PEP 0566.81        """82 83        def transform(key):84            value = self.get_all(key) if key in self.multiple_use_keys else self[key]85            if key == 'Keywords':86                value = re.split(r'\s+', value)87            tk = key.lower().replace('-', '_')88            return tk, value89 90        return dict(map(transform, map(FoldedCase, self)))91