def test_roundtrip(self):
# Write data to file
fp = memmap(self.tmpfp, dtype=self.dtype, mode='w+', shape=self.shape)
fp[:] = self.data[:]
del fp # Test __del__ machinery, which handles cleanup
# Read data back from file
newfp = memmap(self.tmpfp,
dtype=self.dtype,
mode='r',
shape=self.shape)
assert_(allclose(self.data, newfp))
assert_array_equal(self.data, newfp)
assert_equal(newfp.flags.writeable, False)
def test_getitem(self):
fp = memmap(self.tmpfp, dtype=self.dtype, shape=self.shape)
fp[:] = self.data
assert_(fp[1:, :-1].__class__ is memmap)
# Fancy indexing returns a copy that is not memmapped
assert_(fp[[0, 1]].__class__ is ndarray)
def test_view(self):
fp = memmap(self.tmpfp, dtype=self.dtype, shape=self.shape)
new1 = fp.view()
new2 = new1.view()
assert_(new1.base is fp)
assert_(new2.base is fp)
new_array = asarray(fp)
assert_(new_array.base is fp)
def test_filename(self):
tmpname = mktemp('', 'mmap', dir=self.tempdir)
fp = memmap(tmpname, dtype=self.dtype, mode='w+', shape=self.shape)
abspath = os.path.abspath(tmpname)
fp[:] = self.data[:]
assert_equal(abspath, fp.filename)
b = fp[:1]
assert_equal(abspath, b.filename)
del b
del fp
def test_attributes(self):
offset = 1
mode = "w+"
fp = memmap(self.tmpfp,
dtype=self.dtype,
mode=mode,
shape=self.shape,
offset=offset)
assert_equal(offset, fp.offset)
assert_equal(mode, fp.mode)
del fp
def test_del(self):
# Make sure a view does not delete the underlying mmap
fp_base = memmap(self.tmpfp,
dtype=self.dtype,
mode='w+',
shape=self.shape)
fp_base[0] = 5
fp_view = fp_base[0:1]
assert_equal(fp_view[0], 5)
del fp_view
# Should still be able to access and assign values after
# deleting the view
assert_equal(fp_base[0], 5)
fp_base[0] = 6
assert_equal(fp_base[0], 6)
def test_path(self):
tmpname = mktemp('', 'mmap', dir=self.tempdir)
fp = memmap(Path(tmpname),
dtype=self.dtype,
mode='w+',
shape=self.shape)
# os.path.realpath does not resolve symlinks on Windows
# see: https://bugs.python.org/issue9949
# use Path.resolve, just as memmap class does internally
abspath = str(Path(tmpname).resolve())
fp[:] = self.data[:]
assert_equal(abspath, str(fp.filename.resolve()))
b = fp[:1]
assert_equal(abspath, str(b.filename.resolve()))
del b
del fp
def test_ufunc_return_ndarray(self):
fp = memmap(self.tmpfp, dtype=self.dtype, shape=self.shape)
fp[:] = self.data
with suppress_warnings() as sup:
sup.filter(FutureWarning, "np.average currently does not preserve")
for unary_op in [sum, average, product]:
result = unary_op(fp)
assert_(isscalar(result))
assert_(result.__class__ is self.data[0, 0].__class__)
assert_(unary_op(fp, axis=0).__class__ is ndarray)
assert_(unary_op(fp, axis=1).__class__ is ndarray)
for binary_op in [add, subtract, multiply]:
assert_(binary_op(fp, self.data).__class__ is ndarray)
assert_(binary_op(self.data, fp).__class__ is ndarray)
assert_(binary_op(fp, fp).__class__ is ndarray)
fp += 1
assert (fp.__class__ is memmap)
add(fp, 1, out=fp)
assert (fp.__class__ is memmap)
def test_unnamed_file(self):
with TemporaryFile() as f:
fp = memmap(f, dtype=self.dtype, shape=self.shape)
del fp
def test_open_with_filename(self):
tmpname = mktemp('', 'mmap', dir=self.tempdir)
fp = memmap(tmpname, dtype=self.dtype, mode='w+', shape=self.shape)
fp[:] = self.data[:]
del fp
def test_mmap_offset_greater_than_allocation_granularity(self):
size = 5 * mmap.ALLOCATIONGRANULARITY
offset = mmap.ALLOCATIONGRANULARITY + 1
fp = memmap(self.tmpfp, shape=size, mode='w+', offset=offset)
assert_(fp.offset == offset)
def test_slicing_keeps_references(self):
fp = memmap(self.tmpfp, dtype=self.dtype, mode='w+', shape=self.shape)
assert_(fp[:2, :2]._mmap is fp._mmap)
def test_indexing_drops_references(self):
fp = memmap(self.tmpfp, dtype=self.dtype, mode='w+', shape=self.shape)
tmp = fp[(1, 2), (2, 3)]
if isinstance(tmp, memmap):
assert_(tmp._mmap is not fp._mmap)
def test_arithmetic_drops_references(self):
fp = memmap(self.tmpfp, dtype=self.dtype, mode='w+', shape=self.shape)
tmp = (fp + 10)
if isinstance(tmp, memmap):
assert_(tmp._mmap is not fp._mmap)
def test_filename_fileobj(self):
fp = memmap(self.tmpfp, dtype=self.dtype, mode="w+", shape=self.shape)
assert_equal(fp.filename, self.tmpfp.name)
def test_no_shape(self):
self.tmpfp.write(b'a' * 16)
mm = memmap(self.tmpfp, dtype='float64')
assert_equal(mm.shape, (2, ))
def open_memmap(filename,
mode='r+',
dtype=None,
shape=None,
fortran_order=False,
version=None):
"""
Open a .npy file as a memory-mapped array.
This may be used to read an existing file or create a new one.
Parameters
----------
filename : str
The name of the file on disk. This may *not* be a file-like
object.
mode : str, optional
The mode in which to open the file; the default is 'r+'. In
addition to the standard file modes, 'c' is also accepted to mean
"copy on write." See `memmap` for the available mode strings.
dtype : data-type, optional
The data type of the array if we are creating a new file in "write"
mode, if not, `dtype` is ignored. The default value is None, which
results in a data-type of `float64`.
shape : tuple of int
The shape of the array if we are creating a new file in "write"
mode, in which case this parameter is required. Otherwise, this
parameter is ignored and is thus optional.
fortran_order : bool, optional
Whether the array should be Fortran-contiguous (True) or
C-contiguous (False, the default) if we are creating a new file in
"write" mode.
version : tuple of int (major, minor) or None
If the mode is a "write" mode, then this is the version of the file
format used to create the file. None means use the oldest
supported version that is able to store the data. Default: None
Returns
-------
marray : memmap
The memory-mapped array.
Raises
------
ValueError
If the data or the mode is invalid.
IOError
If the file is not found or cannot be opened correctly.
See Also
--------
memmap
"""
if not isinstance(filename, basestring):
raise ValueError("Filename must be a string. Memmap cannot use"
" existing file handles.")
if 'w' in mode:
# We are creating the file, not reading it.
# Check if we ought to create the file.
_check_version(version)
# Ensure that the given dtype is an authentic dtype object rather
# than just something that can be interpreted as a dtype object.
dtype = numpy1.dtype(dtype)
if dtype.hasobject:
msg = "Array can't be memory-mapped: Python objects in dtype."
raise ValueError(msg)
d = dict(
descr=dtype_to_descr(dtype),
fortran_order=fortran_order,
shape=shape,
)
# If we got here, then it should be safe to create the file.
fp = open(filename, mode + 'b')
try:
used_ver = _write_array_header(fp, d, version)
# this warning can be removed when 1.9 has aged enough
if version != (2, 0) and used_ver == (2, 0):
warnings.warn(
"Stored array in format 2.0. It can only be"
"read by NumPy >= 1.9",
UserWarning,
stacklevel=2)
offset = fp.tell()
finally:
fp.close()
else:
# Read the header of the file first.
fp = open(filename, 'rb')
try:
version = read_magic(fp)
_check_version(version)
shape, fortran_order, dtype = _read_array_header(fp, version)
if dtype.hasobject:
msg = "Array can't be memory-mapped: Python objects in dtype."
raise ValueError(msg)
offset = fp.tell()
finally:
fp.close()
if fortran_order:
order = 'F'
else:
order = 'C'
# We need to change a write-only mode to a read-write mode since we've
# already written data to the file.
if mode == 'w+':
mode = 'r+'
marray = numpy1.memmap(filename,
dtype=dtype,
shape=shape,
order=order,
mode=mode,
offset=offset)
return marray
def test_flush(self):
fp = memmap(self.tmpfp, dtype=self.dtype, mode='w+', shape=self.shape)
fp[:] = self.data[:]
assert_equal(fp[0], self.data[0])
fp.flush()