.

lib/tests/test_xnumpy.py

+# -*- coding: utf-8 -*-
+# Copyright (C) 2018  Nexedi SA and Contributors.
+#                     Kirill Smelkov <kirr@nexedi.com>
+#
+# This program is free software: you can Use, Study, Modify and Redistribute
+# it under the terms of the GNU General Public License version 3, or (at your
+# option) any later version, as published by the Free Software Foundation.
+#
+# You can also Link and Combine this program with other software covered by
+# the terms of any of the Free Software licenses or any of the Open Source
+# Initiative approved licenses and Convey the resulting work. Corresponding
+# source of such a combination shall include the source code for all other
+# software used.
+#
+# This program is distributed WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+#
+# See COPYING file for full licensing terms.
+# See https://www.nexedi.com/licensing for rationale and options.
+
+from numpy import arange, dtype, int32
+from wendelin.lib.xnumpy import restructure
+
+# XXX text
+def test_restructure():
+    a = arange(3*3, dtype=int32).reshape((3,3))
+    b = a[:2,:2]
+    dtxy = dtype([('x', int32), ('y', int32)])
+    bxy = restructure(b, dtxy)
+    assert bxy.dtype == dtxy
+    assert bxy.shape == (2,)
+    assert (0, 1) == (0, 1)
+    assert bxy[0]['x'] == 0
+    assert bxy[0]['y'] == 1
+    assert bxy[1]['x'] == 3
+    assert bxy[1]['y'] == 4
+    bxy['x'][0] = 100
+    assert bxy[0]['x'] == 100
+    assert b[0,0] == 100
+    assert a[0,0] == 100
+    bxy['y'][1] = 200
+    assert bxy[1]['y'] == 200
+    assert b[1,1] == 200
+    assert a[1,1] == 200

lib/xnumpy.py

@@ -21,6 +21,7 @@
 import numpy as np
 from numpy.lib import stride_tricks as npst
 
+# XXX move ArrayRef here.
 
 # restructure creates view of the array interpreting its minor axis as fully covered by dtype.
 #
@@ -44,23 +45,23 @@ from numpy.lib import stride_tricks as npst
 # array([[0, 1],
 #        [3, 4]], dtype=int32)
 #
-# In [5]: b.view(np.int64)
+# In [5]: dtxy = np.dtype([('x', np.int32), ('y', np.int32)])
+#
+# In [6]: dtxy
+# Out[6]: dtype([('x', '<i4'), ('y', '<i4')])
+
+# In [7]: b.view(dtxy)
 # ---------------------------------------------------------------------------
 # ValueError                                Traceback (most recent call last)
 # <ipython-input-66-af98529aa150> in <module>()
-# ----> 1 b.view(np.int64)
+# ----> 1 b.view(dtxy)
 #
 # ValueError: To change to a dtype of a different size, the array must be C-contiguous
 #
-# In [6]: restructure(b, np.int64)
-# Out[6]: array([ 4294967296, 17179869187])
-#
-# In [7]: restructure(b, [('x', np.int32), ('y', np.int32)])
-# Out[7]: array([(0, 1), (3, 4)], dtype=[('x', '<i4'), ('y', '<i4')])
+# In [8]: restructure(b, dtxy)
+# Out[8]: array([(0, 1), (3, 4)], dtype=[('x', '<i4'), ('y', '<i4')])
 #
 # restructure always creates view and never copies data.
-#
-# TODO tests
 def restructure(arr, dtype):
     dtype = np.dtype(dtype) # convenience