mirror of
https://github.com/PiBrewing/craftbeerpi4.git
synced 2024-11-13 02:37:53 +01:00
35 lines
996 B
Python
35 lines
996 B
Python
|
from typing import ChainMap, MutableMapping, TypeVar, cast
|
||
|
|
|
||
|
|
_KT = TypeVar("_KT")
|
||
|
|
_VT = TypeVar("_VT")
|
||
|
|
|
||
|
|
|
||
|
|
class DeepChainMap(ChainMap[_KT, _VT]):
|
||
|
|
"""
|
||
|
|
Variant of ChainMap that allows direct updates to inner scopes.
|
||
|
|
|
||
|
|
Only works when all passed mapping are mutable.
|
||
|
|
"""
|
||
|
|
|
||
|
|
def __setitem__(self, key: _KT, value: _VT) -> None:
|
||
|
|
for mapping in self.maps:
|
||
|
|
mutable_mapping = cast(MutableMapping[_KT, _VT], mapping)
|
||
|
|
if key in mutable_mapping:
|
||
|
|
mutable_mapping[key] = value
|
||
|
|
return
|
||
|
|
cast(MutableMapping[_KT, _VT], self.maps[0])[key] = value
|
||
|
|
|
||
|
|
def __delitem__(self, key: _KT) -> None:
|
||
|
|
"""
|
||
|
|
Raises
|
||
|
|
------
|
||
|
|
KeyError
|
||
|
|
If `key` doesn't exist.
|
||
|
|
"""
|
||
|
|
for mapping in self.maps:
|
||
|
|
mutable_mapping = cast(MutableMapping[_KT, _VT], mapping)
|
||
|
|
if key in mapping:
|
||
|
|
del mutable_mapping[key]
|
||
|
|
return
|
||
|
|
raise KeyError(key)
|