def test_void_scalar_structured_data(self):
dt = np.dtype([('name', np.unicode_, 16),
('grades', np.float64, (2, ))])
x = np.array(('ndarray_scalar', (1.2, 3.0)), dtype=dt)[()]
assert_(isinstance(x, np.void))
mv_x = memoryview(x)
expected_size = 16 * np.dtype((np.unicode_, 1)).itemsize
expected_size += 2 * np.dtype(np.float64).itemsize
assert_equal(mv_x.itemsize, expected_size)
assert_equal(mv_x.ndim, 0)
assert_equal(mv_x.shape, ())
assert_equal(mv_x.strides, ())
assert_equal(mv_x.suboffsets, ())
# check scalar format string against ndarray format string
a = np.array([('Sarah', (8.0, 7.0)), ('John', (6.0, 7.0))], dtype=dt)
assert_(isinstance(a, np.ndarray))
mv_a = memoryview(a)
assert_equal(mv_x.itemsize, mv_a.itemsize)
assert_equal(mv_x.format, mv_a.format)
# Check that we do not allow writeable buffer export (technically
# we could allow it sometimes here...)
with pytest.raises(BufferError, match="scalar buffer is readonly"):
get_buffer_info(x, ["WRITABLE"])
def test_datetime_memoryview(self):
# gh-11656
# Values verified with v1.13.3, shape is not () as in test_scalar_dim
dt1 = np.datetime64('2016-01-01')
dt2 = np.datetime64('2017-01-01')
expected = dict(strides=(1, ),
itemsize=1,
ndim=1,
shape=(8, ),
format='B',
readonly=True)
v = memoryview(dt1)
assert self._as_dict(v) == expected
v = memoryview(dt2 - dt1)
assert self._as_dict(v) == expected
dt = np.dtype([('a', 'uint16'), ('b', 'M8[s]')])
a = np.empty(1, dt)
# Fails to create a PEP 3118 valid buffer
assert_raises((ValueError, BufferError), memoryview, a[0])
# Check that we do not allow writeable buffer export
with pytest.raises(BufferError, match="scalar buffer is readonly"):
get_buffer_info(dt1, ["WRITABLE"])
def test_user_scalar_fails_buffer(self):
r = rational(1)
with assert_raises(TypeError):
memoryview(r)
# Check that we do not allow writeable buffer export
with pytest.raises(BufferError, match="scalar buffer is readonly"):
get_buffer_info(r, ["WRITABLE"])
def test_str_ucs4(self, s):
s = np.str_(s) # only our subclass implements the buffer protocol
# all the same, characters always encode as ucs4
expected = dict(strides=(), itemsize=8, ndim=0, shape=(), format='2w',
readonly=True)
v = memoryview(s)
assert self._as_dict(v) == expected
# integers of the paltform-appropriate endianness
code_points = np.frombuffer(v, dtype='i4')
assert_equal(code_points, [ord(c) for c in s])
# Check that we do not allow writeable buffer export
with pytest.raises(BufferError, match="scalar buffer is readonly"):
get_buffer_info(s, ["WRITABLE"])
def test_scalar_buffers_readonly(self, scalar):
x = scalar()
with pytest.raises(BufferError, match="scalar buffer is readonly"):
get_buffer_info(x, ["WRITABLE"])
