Class _Environ

Lib/os.py:696–767

from _collections_abc import MutableMapping, Mapping

class _Environ(MutableMapping):
    def __init__(self, data, encodekey, decodekey, encodevalue, decodevalue):
        self.encodekey = encodekey
        self.decodekey = decodekey
        self.encodevalue = encodevalue
        self.decodevalue = decodevalue
        self._data = data

    def __getitem__(self, key):
        try:
            value = self._data[self.encodekey(key)]
        except KeyError:
            # raise KeyError with the original key value
            raise KeyError(key) from None
        return self.decodevalue(value)

    def __setitem__(self, key, value):
        key = self.encodekey(key)
        value = self.encodevalue(value)
        putenv(key, value)
        self._data[key] = value

    def __delitem__(self, key):
        encodedkey = self.encodekey(key)
        unsetenv(encodedkey)
        try:
            del self._data[encodedkey]
        except KeyError:
            # raise KeyError with the original key value
            raise KeyError(key) from None

    def __iter__(self):
        # list() from dict object is an atomic operation
        keys = list(self._data)
        for key in keys:
            yield self.decodekey(key)

    def __len__(self):
        return len(self._data)

    def __repr__(self):
        formatted_items = ", ".join(
            f"{self.decodekey(key)!r}: {self.decodevalue(value)!r}"
            for key, value in self._data.items()
        )
        return f"environ({{{formatted_items}}})"

    def copy(self):
        return dict(self)

    def setdefault(self, key, value):
        if key not in self:
            self[key] = value
        return self[key]

    def __ior__(self, other):
        self.update(other)
        return self