Add *_impl file

mtsokol · mtsokol · commit 1fe19c6d8889 · 2023-08-26T18:47:01.000+02:00
diff --git a/numpy/lib/_array_utils_impl.py b/numpy/lib/_array_utils_impl.py
@@ -0,0 +1,57 @@
+from numpy.core import asarray
+from numpy.core.numeric import normalize_axis_tuple, normalize_axis_index
+
+
+__all__ = ["byte_bounds", "normalize_axis_tuple", "normalize_axis_index"]
+
+
+def byte_bounds(a):
+    """
+    Returns pointers to the end-points of an array.
+
+    Parameters
+    ----------
+    a : ndarray
+        Input array. It must conform to the Python-side of the array
+        interface.
+
+    Returns
+    -------
+    (low, high) : tuple of 2 integers
+        The first integer is the first byte of the array, the second
+        integer is just past the last byte of the array.  If `a` is not
+        contiguous it will not use every byte between the (`low`, `high`)
+        values.
+
+    Examples
+    --------
+    >>> I = np.eye(2, dtype='f'); I.dtype
+    dtype('float32')
+    >>> low, high = np.byte_bounds(I)
+    >>> high - low == I.size*I.itemsize
+    True
+    >>> I = np.eye(2); I.dtype
+    dtype('float64')
+    >>> low, high = np.byte_bounds(I)
+    >>> high - low == I.size*I.itemsize
+    True
+
+    """
+    ai = a.__array_interface__
+    a_data = ai['data'][0]
+    astrides = ai['strides']
+    ashape = ai['shape']
+    bytes_a = asarray(a).dtype.itemsize
+
+    a_low = a_high = a_data
+    if astrides is None:
+        # contiguous case
+        a_high += a.size * bytes_a
+    else:
+        for shape, stride in zip(ashape, astrides):
+            if stride < 0:
+                a_low += (shape-1)*stride
+            else:
+                a_high += (shape-1)*stride
+        a_high += bytes_a
+    return a_low, a_high
diff --git a/numpy/lib/_array_utils_impl.pyi b/numpy/lib/_array_utils_impl.pyi
@@ -0,0 +1,22 @@
+from typing import Any, Iterable, Tuple
+
+from numpy import ndarray, generic
+
+# NOTE: In practice `byte_bounds` can (potentially) take any object
+# implementing the `__array_interface__` protocol. The caveat is
+# that certain keys, marked as optional in the spec, must be present for
+#  `byte_bounds`. This concerns `"strides"` and `"data"`.
+def byte_bounds(a: generic | ndarray[Any, Any]) -> tuple[int, int]: ...
+
+def normalize_axis_tuple(
+    axis: int | Iterable[int], 
+    ndim: int = ..., 
+    argname: None | str = ..., 
+    allow_duplicate: None | bool = ...,
+) -> Tuple[int, int]: ...
+
+def normalize_axis_index(
+    axis: int = ...,
+    ndim: int = ...,
+    msg_prefix: None | str = ...,
+) -> int: ...
diff --git a/numpy/lib/array_utils.py b/numpy/lib/array_utils.py
@@ -1,57 +1,5 @@
-from numpy.core import asarray
-from numpy.core.numeric import normalize_axis_tuple, normalize_axis_index
-
-
-__all__ = ["byte_bounds", "normalize_axis_tuple", "normalize_axis_index"]
-
-
-def byte_bounds(a):
-    """
-    Returns pointers to the end-points of an array.
-
-    Parameters
-    ----------
-    a : ndarray
-        Input array. It must conform to the Python-side of the array
-        interface.
-
-    Returns
-    -------
-    (low, high) : tuple of 2 integers
-        The first integer is the first byte of the array, the second
-        integer is just past the last byte of the array.  If `a` is not
-        contiguous it will not use every byte between the (`low`, `high`)
-        values.
-
-    Examples
-    --------
-    >>> I = np.eye(2, dtype='f'); I.dtype
-    dtype('float32')
-    >>> low, high = np.byte_bounds(I)
-    >>> high - low == I.size*I.itemsize
-    True
-    >>> I = np.eye(2); I.dtype
-    dtype('float64')
-    >>> low, high = np.byte_bounds(I)
-    >>> high - low == I.size*I.itemsize
-    True
-
-    """
-    ai = a.__array_interface__
-    a_data = ai['data'][0]
-    astrides = ai['strides']
-    ashape = ai['shape']
-    bytes_a = asarray(a).dtype.itemsize
-
-    a_low = a_high = a_data
-    if astrides is None:
-        # contiguous case
-        a_high += a.size * bytes_a
-    else:
-        for shape, stride in zip(ashape, astrides):
-            if stride < 0:
-                a_low += (shape-1)*stride
-            else:
-                a_high += (shape-1)*stride
-        a_high += bytes_a
-    return a_low, a_high
+from ._array_utils_impl import (
+    byte_bounds,
+    normalize_axis_index,
+    normalize_axis_tuple,
+)
diff --git a/numpy/lib/array_utils.pyi b/numpy/lib/array_utils.pyi
@@ -1,22 +1,5 @@
-from typing import Any, Iterable, Tuple
-
-from numpy import ndarray, generic
-
-# NOTE: In practice `byte_bounds` can (potentially) take any object
-# implementing the `__array_interface__` protocol. The caveat is
-# that certain keys, marked as optional in the spec, must be present for
-#  `byte_bounds`. This concerns `"strides"` and `"data"`.
-def byte_bounds(a: generic | ndarray[Any, Any]) -> tuple[int, int]: ...
-
-def normalize_axis_tuple(
-    axis: int | Iterable[int], 
-    ndim: int = ..., 
-    argname: None | str = ..., 
-    allow_duplicate: None | bool = ...,
-) -> Tuple[int, int]: ...
-
-def normalize_axis_index(
-    axis: int = ...,
-    ndim: int = ...,
-    msg_prefix: None | str = ...,
-) -> int: ...
+from ._array_utils_impl import (
+    byte_bounds as byte_bounds,
+    normalize_axis_index as normalize_axis_index,
+    normalize_axis_tuple as normalize_axis_tuple,
+)
