TYP: stubs for reshape, ops, ops_dispatch, hashing (#40455)

Author: jbrockmendel

pandas/_libs/hashing.pyi

@@ -0,0 +1,7 @@
+import numpy as np
+
+def hash_object_array(
+    arr: np.ndarray,  # np.ndarray[object]
+    key: str,
+    encoding: str = ...,
+) -> np.ndarray: ...  # np.ndarray[np.uint64]

pandas/_libs/ops.pyi

@@ -0,0 +1,43 @@
+from typing import (
+    Any,
+    Callable,
+)
+
+import numpy as np
+
+_BinOp = Callable[[Any, Any], Any]
+_BoolOp = Callable[[Any, Any], bool]
+
+
+def scalar_compare(
+    values: np.ndarray,  # object[:]
+    val: object,
+    op: _BoolOp,          # {operator.eq, operator.ne, ...}
+) -> np.ndarray: ...     # np.ndarray[bool]
+
+def vec_compare(
+    left: np.ndarray,   # np.ndarray[object]
+    right: np.ndarray,  # np.ndarray[object]
+    op: _BoolOp,         # {operator.eq, operator.ne, ...}
+) -> np.ndarray: ...    # np.ndarray[bool]
+
+
+def scalar_binop(
+    values: np.ndarray,   # object[:]
+    val: object,
+    op: _BinOp,           # binary operator
+) -> np.ndarray: ...
+
+
+def vec_binop(
+    left: np.ndarray,   # object[:]
+    right: np.ndarray,  # object[:]
+    op: _BinOp,         # binary operator
+) -> np.ndarray: ...
+
+
+def maybe_convert_bool(
+    arr: np.ndarray,  # np.ndarray[object]
+    true_values=...,
+    false_values=...
+) -> np.ndarray: ...

pandas/_libs/ops_dispatch.pyi

@@ -0,0 +1,5 @@
+import numpy as np
+
+def maybe_dispatch_ufunc_to_dunder_op(
+    self, ufunc: np.ufunc, method: str, *inputs, **kwargs
+): ...

pandas/_libs/reshape.pyi

@@ -0,0 +1,19 @@
+import numpy as np
+
+def unstack(
+    values: np.ndarray,    # reshape_t[:, :]
+    mask: np.ndarray,      # const uint8_t[:]
+    stride: int,
+    length: int,
+    width: int,
+    new_values: np.ndarray,  # reshape_t[:, :]
+    new_mask: np.ndarray,    # uint8_t[:, :]
+) -> None: ...
+
+
+def explode(
+    values: np.ndarray,  # np.ndarray[object]
+) -> tuple[
+    np.ndarray,  # np.ndarray[object]
+    np.ndarray,  # np.ndarray[np.int64]
+]: ...