CLN: Move DeepChainMap to only location used (#51314)

Author: mroeschke

pandas/compat/chainmap.py

@@ -3,10 +3,7 @@
 
 import ast
 from functools import partial
-from typing import (
-    TYPE_CHECKING,
-    Any,
-)
+from typing import Any
 
 import numpy as np
 
@@ -36,9 +33,6 @@
     pprint_thing_encoded,
 )
 
-if TYPE_CHECKING:
-    from pandas.compat.chainmap import DeepChainMap
-
 
 class PyTablesScope(_scope.Scope):
     __slots__ = ("queryables",)
@@ -567,7 +561,7 @@ def __init__(
         self._visitor = None
 
         # capture the environment if needed
-        local_dict: DeepChainMap[Any, Any] | None = None
+        local_dict: _scope.DeepChainMap[Any, Any] | None = None
 
         if isinstance(where, PyTablesExpr):
             local_dict = where.env.scope

pandas/core/computation/pytables.py

@@ -10,16 +10,51 @@
 import pprint
 import struct
 import sys
+from typing import (
+    ChainMap,
+    TypeVar,
+)
 
 import numpy as np
 
 from pandas._libs.tslibs import Timestamp
-from pandas.compat.chainmap import DeepChainMap
 from pandas.errors import UndefinedVariableError
 
+_KT = TypeVar("_KT")
+_VT = TypeVar("_VT")
+
+
+# https://docs.python.org/3/library/collections.html#chainmap-examples-and-recipes
+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:
+            if key in mapping:
+                mapping[key] = value
+                return
+        self.maps[0][key] = value
+
+    def __delitem__(self, key: _KT) -> None:
+        """
+        Raises
+        ------
+        KeyError
+            If `key` doesn't exist.
+        """
+        for mapping in self.maps:
+            if key in mapping:
+                del mapping[key]
+                return
+        raise KeyError(key)
+
 
 def ensure_scope(
-    level: int, global_dict=None, local_dict=None, resolvers=(), target=None, **kwargs
+    level: int, global_dict=None, local_dict=None, resolvers=(), target=None
 ) -> Scope:
     """Ensure that we are grabbing the correct scope."""
     return Scope(