TYP: core.computations.scope

pandas/compat/chainmap.py

@@ -15,3 +15,8 @@ def __delitem__(self, key):
                 del mapping[key]
                 return
         raise KeyError(key)
+
+    def new_child(self, *args, **kwargs) -> "DeepChainMap":
+        # ChainMap.new_child returns self.__class__(...) but mypy
+        #  doesn't know that, so we annotate it explicitly here.
+        return super().new_child(*args, **kwargs)  # type: ignore

pandas/core/computation/eval.py

@@ -11,7 +11,7 @@
 
 from pandas.core.computation.engines import _engines
 from pandas.core.computation.expr import Expr, _parsers, tokenize_string
-from pandas.core.computation.scope import _ensure_scope
+from pandas.core.computation.scope import ensure_scope
 
 from pandas.io.formats.printing import pprint_thing
 
@@ -309,7 +309,7 @@ def eval(
         _check_for_locals(expr, level, parser)
 
         # get our (possibly passed-in) scope
-        env = _ensure_scope(
+        env = ensure_scope(
             level + 1,
             global_dict=global_dict,
             local_dict=local_dict,

pandas/core/computation/pytables.py

@@ -13,15 +13,15 @@
 
 import pandas as pd
 import pandas.core.common as com
-from pandas.core.computation import expr, ops
+from pandas.core.computation import expr, ops, scope as _scope
 from pandas.core.computation.common import _ensure_decoded
 from pandas.core.computation.expr import BaseExprVisitor
 from pandas.core.computation.ops import UndefinedVariableError, is_term
 
 from pandas.io.formats.printing import pprint_thing, pprint_thing_encoded
 
 
-class Scope(expr.Scope):
+class Scope(_scope.Scope):
     __slots__ = ("queryables",)
 
     def __init__(self, level, global_dict=None, local_dict=None, queryables=None):

pandas/core/computation/scope.py

@@ -1,24 +1,24 @@
 """
 Module for scope operations
 """
-
 import datetime
 import inspect
 from io import StringIO
 import itertools
 import pprint
 import struct
 import sys
+from typing import Any, List, MutableMapping
 
 import numpy as np
 
 from pandas._libs.tslibs import Timestamp
 from pandas.compat.chainmap import DeepChainMap
 
 
-def _ensure_scope(
-    level, global_dict=None, local_dict=None, resolvers=(), target=None, **kwargs
-):
+def ensure_scope(
+    level: int, global_dict=None, local_dict=None, resolvers=(), target=None, **kwargs
+) -> "Scope":
     """Ensure that we are grabbing the correct scope."""
     return Scope(
         level + 1,
@@ -104,22 +104,28 @@ class Scope:
     """
 
     __slots__ = ["level", "scope", "target", "resolvers", "temps"]
+    level: int
+    scope: DeepChainMap
+    resolvers: DeepChainMap
+    temps: MutableMapping[str, Any]
 
     def __init__(
-        self, level, global_dict=None, local_dict=None, resolvers=(), target=None
+        self, level: int, global_dict=None, local_dict=None, resolvers=(), target=None,
     ):
         self.level = level + 1
 
         # shallow copy because we don't want to keep filling this up with what
-        # was there before if there are multiple calls to Scope/_ensure_scope
+        # was there before if there are multiple calls to Scope/ensure_scope
         self.scope = DeepChainMap(_DEFAULT_GLOBALS.copy())
         self.target = target
 
+        assert all(isinstance(x, str) for x in self.scope), self.scope
+
         if isinstance(local_dict, Scope):
             self.scope.update(local_dict.scope)
             if local_dict.target is not None:
                 self.target = local_dict.target
-            self.update(local_dict.level)
+            self._update(local_dict.level)
 
         frame = sys._getframe(self.level)
 
@@ -161,7 +167,7 @@ def has_resolvers(self) -> bool:
         """
         return bool(len(self.resolvers))
 
-    def resolve(self, key, is_local):
+    def resolve(self, key: str, is_local: bool):
         """
         Resolve a variable name in a possibly local context.
 
@@ -203,7 +209,7 @@ def resolve(self, key, is_local):
 
                 raise UndefinedVariableError(key, is_local)
 
-    def swapkey(self, old_key, new_key, new_value=None):
+    def swapkey(self, old_key: str, new_key: str, new_value=None):
         """
         Replace a variable name, with a potentially new value.
 
@@ -216,10 +222,14 @@ def swapkey(self, old_key, new_key, new_value=None):
         new_value : object
             Value to be replaced along with the possible renaming
         """
+        maps: List[MutableMapping]
+        mapping: MutableMapping
+
+        # TODO: convince mypy that these maps are in fact mutable
         if self.has_resolvers:
-            maps = self.resolvers.maps + self.scope.maps
+            maps = self.resolvers.maps + self.scope.maps  # type: ignore
         else:
-            maps = self.scope.maps
+            maps = self.scope.maps  # type: ignore
 
         maps.append(self.temps)
 
@@ -228,7 +238,7 @@ def swapkey(self, old_key, new_key, new_value=None):
                 mapping[new_key] = new_value
                 return
 
-    def _get_vars(self, stack, scopes):
+    def _get_vars(self, stack, scopes: List[str]):
         """
         Get specifically scoped variables from a list of stack frames.
 
@@ -241,17 +251,17 @@ def _get_vars(self, stack, scopes):
             evaluate to a dictionary. For example, ('locals', 'globals')
         """
         variables = itertools.product(scopes, stack)
-        for scope, (frame, _, _, _, _, _) in variables:
+        for name, (frame, _, _, _, _, _) in variables:
             try:
-                d = getattr(frame, "f_" + scope)
+                d = getattr(frame, "f_" + name)
                 self.scope = self.scope.new_child(d)
             finally:
                 # won't remove it, but DECREF it
                 # in Py3 this probably isn't necessary since frame won't be
                 # scope after the loop
                 del frame
 
-    def update(self, level: int):
+    def _update(self, level: int):
         """
         Update the current scope by going back `level` levels.
 
@@ -303,7 +313,7 @@ def ntemps(self) -> int:
         return len(self.temps)
 
     @property
-    def full_scope(self):
+    def full_scope(self) -> DeepChainMap:
         """
         Return the full scope for use with passing to engines transparently
         as a mapping.
@@ -313,5 +323,6 @@ def full_scope(self):
         vars : DeepChainMap
             All variables in this scope.
         """
-        maps = [self.temps] + self.resolvers.maps + self.scope.maps
+        # TODO: convince mypy that all of the maps are mutable
+        maps = [self.temps] + self.resolvers.maps + self.scope.maps  # type: ignore
         return DeepChainMap(*maps)