ext/pybind11/tests/test_buffers.py

   1 import struct
   2 import pytest
   3 from pybind11_tests import buffers as m
   4 from pybind11_tests import ConstructorStats
   5
   6 pytestmark = pytest.requires_numpy
   7
   8 with pytest.suppress(ImportError):
   9     import numpy as np
  10
  11
  12 def test_from_python():
  13     with pytest.raises(RuntimeError) as excinfo:
  14         m.Matrix(np.array([1, 2, 3]))  # trying to assign a 1D array
  15     assert str(excinfo.value) == "Incompatible buffer format!"
  16
  17     m3 = np.array([[1, 2, 3], [4, 5, 6]]).astype(np.float32)
  18     m4 = m.Matrix(m3)
  19
  20     for i in range(m4.rows()):
  21         for j in range(m4.cols()):
  22             assert m3[i, j] == m4[i, j]
  23
  24     cstats = ConstructorStats.get(m.Matrix)
  25     assert cstats.alive() == 1
  26     del m3, m4
  27     assert cstats.alive() == 0
  28     assert cstats.values() == ["2x3 matrix"]
  29     assert cstats.copy_constructions == 0
  30     # assert cstats.move_constructions >= 0  # Don't invoke any
  31     assert cstats.copy_assignments == 0
  32     assert cstats.move_assignments == 0
  33
  34
  35 # PyPy: Memory leak in the "np.array(m, copy=False)" call
  36 # https://bitbucket.org/pypy/pypy/issues/2444
  37 @pytest.unsupported_on_pypy
  38 def test_to_python():
  39     mat = m.Matrix(5, 5)
  40     assert memoryview(mat).shape == (5, 5)
  41
  42     assert mat[2, 3] == 0
  43     mat[2, 3] = 4
  44     assert mat[2, 3] == 4
  45
  46     mat2 = np.array(mat, copy=False)
  47     assert mat2.shape == (5, 5)
  48     assert abs(mat2).sum() == 4
  49     assert mat2[2, 3] == 4
  50     mat2[2, 3] = 5
  51     assert mat2[2, 3] == 5
  52
  53     cstats = ConstructorStats.get(m.Matrix)
  54     assert cstats.alive() == 1
  55     del mat
  56     pytest.gc_collect()
  57     assert cstats.alive() == 1
  58     del mat2  # holds a mat reference
  59     pytest.gc_collect()
  60     assert cstats.alive() == 0
  61     assert cstats.values() == ["5x5 matrix"]
  62     assert cstats.copy_constructions == 0
  63     # assert cstats.move_constructions >= 0  # Don't invoke any
  64     assert cstats.copy_assignments == 0
  65     assert cstats.move_assignments == 0
  66
  67
  68 @pytest.unsupported_on_pypy
  69 def test_inherited_protocol():
  70     """SquareMatrix is derived from Matrix and inherits the buffer protocol"""
  71
  72     matrix = m.SquareMatrix(5)
  73     assert memoryview(matrix).shape == (5, 5)
  74     assert np.asarray(matrix).shape == (5, 5)
  75
  76
  77 @pytest.unsupported_on_pypy
  78 def test_pointer_to_member_fn():
  79     for cls in [m.Buffer, m.ConstBuffer, m.DerivedBuffer]:
  80         buf = cls()
  81         buf.value = 0x12345678
  82         value = struct.unpack('i', bytearray(buf))[0]
  83         assert value == 0x12345678