Class CaseInsensitiveDict

scrapy/utils/datatypes.py:102–141

A dict-like structure that accepts strings or bytes as keys and allows case-insensitive lookups.

class CaseInsensitiveDict(collections.UserDict[str | bytes, Any]):
    """A dict-like structure that accepts strings or bytes
    as keys and allows case-insensitive lookups.
    """

    def __init__(self, *args: Any, **kwargs: Any) -> None:
        self._keys: dict[str | bytes, Any] = {}
        super().__init__(*args, **kwargs)

    def __getitem__(self, key: str | bytes) -> Any:
        normalized_key = self._normkey(key)
        return super().__getitem__(self._keys[normalized_key.lower()])

    def __setitem__(self, key: str | bytes, value: Any) -> None:
        normalized_key = self._normkey(key)
        try:
            lower_key = self._keys[normalized_key.lower()]
            del self[lower_key]
        except KeyError:
            pass
        super().__setitem__(normalized_key, self._normvalue(value))
        self._keys[normalized_key.lower()] = normalized_key

    def __delitem__(self, key: str | bytes) -> None:
        normalized_key = self._normkey(key)
        stored_key = self._keys.pop(normalized_key.lower())
        super().__delitem__(stored_key)

    def __contains__(self, key: str | bytes) -> bool:  # type: ignore[override]
        normalized_key = self._normkey(key)
        return normalized_key.lower() in self._keys

    def __repr__(self) -> str:
        return f"<{self.__class__.__name__}: {super().__repr__()}>"

    def _normkey(self, key: str | bytes) -> str | bytes:
        return key

    def _normvalue(self, value: Any) -> Any:
        return value


class LocalCache(OrderedDict[_KT, _VT]):