TYP: Enable mypy stricter typing for partial types

pandas/core/arrays/timedeltas.py

@@ -202,7 +202,7 @@ def dtype(self) -> np.dtype[np.timedelta64]:  # type: ignore[override]
     # ----------------------------------------------------------------
     # Constructors
 
-    _freq = None
+    _freq: Tick | Day | None = None
 
     @classmethod
     def _validate_dtype(cls, values, dtype):

pandas/core/dtypes/common.py

@@ -69,7 +69,7 @@
 INT64_DTYPE = np.dtype(np.int64)
 
 # oh the troubles to reduce import time
-_is_scipy_sparse = None
+_is_scipy_sparse: Callable[[ArrayLike], bool] | None = None
 
 ensure_float64 = algos.ensure_float64
 ensure_int64 = algos.ensure_int64

pandas/core/indexes/base.py

@@ -470,7 +470,7 @@ def _engine_type(
 
     str = Accessor("str", StringMethods)
 
-    _references = None
+    _references: BlockValuesRefs | None = None
 
     # --------------------------------------------------------------------
     # Constructors
@@ -640,7 +640,10 @@ def _dtype_to_subclass(cls, dtype: DtypeObj):
 
     @classmethod
     def _simple_new(
-        cls, values: ArrayLike, name: Hashable | None = None, refs=None
+        cls,
+        values: ArrayLike,
+        name: Hashable | None = None,
+        refs: BlockValuesRefs | None = None,
     ) -> Self:
         """
         We require that we have a dtype compat for the values. If we are passed

pandas/io/excel/_base.py

@@ -1181,9 +1181,6 @@ def __new__(
 
         return object.__new__(cls)
 
-    # declare external properties you can count on
-    _path = None
-
     @property
     def supported_extensions(self) -> tuple[str, ...]:
         """Extensions that writer engine supports."""

pandas/io/pytables.py

@@ -114,7 +114,10 @@
         Iterator,
         Sequence,
     )
-    from types import TracebackType
+    from types import (
+        ModuleType,
+        TracebackType,
+    )
 
     from tables import (
         Col,
@@ -227,7 +230,7 @@ def _ensure_term(where, scope_level: int):
     )
 
 # oh the troubles to reduce import time
-_table_mod = None
+_table_mod: ModuleType | None = None
 _table_file_open_policy_is_strict = False
 
 

pandas/plotting/_matplotlib/converter.py

@@ -63,10 +63,10 @@
     from pandas._libs.tslibs.offsets import BaseOffset
 
 
-_mpl_units = {}  # Cache for units overwritten by us
+_mpl_units: dict = {}  # Cache for units overwritten by us
 
 
-def get_pairs():
+def get_pairs() -> list[tuple[type, type[mdates.DateConverter]]]:
     pairs = [
         (Timestamp, DatetimeConverter),
         (Period, PeriodConverter),

pyproject.toml

@@ -534,7 +534,7 @@ enable_error_code = "ignore-without-code"
 # Miscellaneous strictness flags
 allow_untyped_globals = false
 allow_redefinition = false
-local_partial_types = false
+local_partial_types = true
 implicit_reexport = true
 strict_equality = true
 # Configuring error messages