Merge the lib_for_io branch back into the trunk.

1 files changed, 512 insertions, 0 deletions

diff --git a/numpy/lib/tests/test_format.py b/numpy/lib/tests/test_format.py
new file mode 100644
index 000000000..b238950a3
--- /dev/null
+++ b/numpy/lib/tests/test_format.py
@@ -0,0 +1,512 @@
+r''' Test the .npy file format.
+
+Set up:
+
+    >>> import numpy as np
+    >>> from cStringIO import StringIO
+    >>> from numpy.lib import format
+    >>>
+    >>> scalars = [
+    ...     np.uint8,
+    ...     np.int8,
+    ...     np.uint16,
+    ...     np.int16,
+    ...     np.uint32,
+    ...     np.int32,
+    ...     np.uint64,
+    ...     np.int64,
+    ...     np.float32,
+    ...     np.float64,
+    ...     np.complex64,
+    ...     np.complex128,
+    ...     object,
+    ... ]
+    >>> 
+    >>> basic_arrays = []
+    >>> 
+    >>> for scalar in scalars:
+    ...     for endian in '<>':
+    ...         dtype = np.dtype(scalar).newbyteorder(endian)
+    ...         basic = np.arange(15).astype(dtype)
+    ...         basic_arrays.extend([
+    ...             np.array([], dtype=dtype),
+    ...             np.array(10, dtype=dtype),
+    ...             basic,
+    ...             basic.reshape((3,5)),
+    ...             basic.reshape((3,5)).T,
+    ...             basic.reshape((3,5))[::-1,::2],
+    ...         ])
+    ... 
+    >>> 
+    >>> Pdescr = [
+    ...     ('x', 'i4', (2,)),
+    ...     ('y', 'f8', (2, 2)),
+    ...     ('z', 'u1')]
+    >>> 
+    >>> 
+    >>> PbufferT = [
+    ...     ([3,2], [[6.,4.],[6.,4.]], 8),
+    ...     ([4,3], [[7.,5.],[7.,5.]], 9),
+    ...     ]
+    >>> 
+    >>> 
+    >>> Ndescr = [
+    ...     ('x', 'i4', (2,)),
+    ...     ('Info', [
+    ...         ('value', 'c16'),
+    ...         ('y2', 'f8'),
+    ...         ('Info2', [
+    ...             ('name', 'S2'),
+    ...             ('value', 'c16', (2,)),
+    ...             ('y3', 'f8', (2,)),
+    ...             ('z3', 'u4', (2,))]),
+    ...         ('name', 'S2'),
+    ...         ('z2', 'b1')]),
+    ...     ('color', 'S2'),
+    ...     ('info', [
+    ...         ('Name', 'U8'),
+    ...         ('Value', 'c16')]),
+    ...     ('y', 'f8', (2, 2)),
+    ...     ('z', 'u1')]
+    >>> 
+    >>> 
+    >>> NbufferT = [
+    ...     ([3,2], (6j, 6., ('nn', [6j,4j], [6.,4.], [1,2]), 'NN', True), 'cc', ('NN', 6j), [[6.,4.],[6.,4.]], 8),
+    ...     ([4,3], (7j, 7., ('oo', [7j,5j], [7.,5.], [2,1]), 'OO', False), 'dd', ('OO', 7j), [[7.,5.],[7.,5.]], 9),
+    ...     ]
+    >>> 
+    >>> 
+    >>> record_arrays = [
+    ...     np.array(PbufferT, dtype=np.dtype(Pdescr).newbyteorder('<')),
+    ...     np.array(NbufferT, dtype=np.dtype(Ndescr).newbyteorder('<')),
+    ...     np.array(PbufferT, dtype=np.dtype(Pdescr).newbyteorder('>')),
+    ...     np.array(NbufferT, dtype=np.dtype(Ndescr).newbyteorder('>')),
+    ... ]
+
+Test the magic string writing.
+
+    >>> format.magic(1, 0)
+    '\x93NUMPY\x01\x00'
+    >>> format.magic(0, 0)
+    '\x93NUMPY\x00\x00'
+    >>> format.magic(255, 255)
+    '\x93NUMPY\xff\xff'
+    >>> format.magic(2, 5)
+    '\x93NUMPY\x02\x05'
+
+Test the magic string reading.
+
+    >>> format.read_magic(StringIO(format.magic(1, 0)))
+    (1, 0)
+    >>> format.read_magic(StringIO(format.magic(0, 0)))
+    (0, 0)
+    >>> format.read_magic(StringIO(format.magic(255, 255)))
+    (255, 255)
+    >>> format.read_magic(StringIO(format.magic(2, 5)))
+    (2, 5)
+
+Test the header writing.
+
+    >>> for arr in basic_arrays + record_arrays:
+    ...     f = StringIO()
+    ...     format.write_array_header_1_0(f, arr)
+    ...     print repr(f.getvalue())
+    ... 
+    "F\x00{'descr': '|u1', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '|u1', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '|u1', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '|u1', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '|u1', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '|u1', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '|u1', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '|u1', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '|u1', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '|u1', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '|u1', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '|u1', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '|i1', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '|i1', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '|i1', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '|i1', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '|i1', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '|i1', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '|i1', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '|i1', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '|i1', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '|i1', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '|i1', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '|i1', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '<u2', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '<u2', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '<u2', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '<u2', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '<u2', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '<u2', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '>u2', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '>u2', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '>u2', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '>u2', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '>u2', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '>u2', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '<i2', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '<i2', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '<i2', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '<i2', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '<i2', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '<i2', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '>i2', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '>i2', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '>i2', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '>i2', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '>i2', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '>i2', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '<u4', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '<u4', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '<u4', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '<u4', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '<u4', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '<u4', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '>u4', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '>u4', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '>u4', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '>u4', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '>u4', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '>u4', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '<i4', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '<i4', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '<i4', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '<i4', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '<i4', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '<i4', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '>i4', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '>i4', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '>i4', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '>i4', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '>i4', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '>i4', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '<u8', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '<u8', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '<u8', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '<u8', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '<u8', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '<u8', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '>u8', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '>u8', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '>u8', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '>u8', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '>u8', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '>u8', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '<i8', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '<i8', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '<i8', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '<i8', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '<i8', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '<i8', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '>i8', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '>i8', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '>i8', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '>i8', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '>i8', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '>i8', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '<f4', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '<f4', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '<f4', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '<f4', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '<f4', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '<f4', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '>f4', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '>f4', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '>f4', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '>f4', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '>f4', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '>f4', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '<f8', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '<f8', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '<f8', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '<f8', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '<f8', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '<f8', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '>f8', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '>f8', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '>f8', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '>f8', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '>f8', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '>f8', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '<c8', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '<c8', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '<c8', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '<c8', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '<c8', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '<c8', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '>c8', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '>c8', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '>c8', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '>c8', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '>c8', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '>c8', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '<c16', 'fortran_order': False, 'shape': (0,)}             \n"
+    "F\x00{'descr': '<c16', 'fortran_order': False, 'shape': ()}               \n"
+    "F\x00{'descr': '<c16', 'fortran_order': False, 'shape': (15,)}            \n"
+    "F\x00{'descr': '<c16', 'fortran_order': False, 'shape': (3, 5)}           \n"
+    "F\x00{'descr': '<c16', 'fortran_order': True, 'shape': (5, 3)}            \n"
+    "F\x00{'descr': '<c16', 'fortran_order': False, 'shape': (3, 3)}           \n"
+    "F\x00{'descr': '>c16', 'fortran_order': False, 'shape': (0,)}             \n"
+    "F\x00{'descr': '>c16', 'fortran_order': False, 'shape': ()}               \n"
+    "F\x00{'descr': '>c16', 'fortran_order': False, 'shape': (15,)}            \n"
+    "F\x00{'descr': '>c16', 'fortran_order': False, 'shape': (3, 5)}           \n"
+    "F\x00{'descr': '>c16', 'fortran_order': True, 'shape': (5, 3)}            \n"
+    "F\x00{'descr': '>c16', 'fortran_order': False, 'shape': (3, 3)}           \n"
+    "F\x00{'descr': '|O4', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '|O4', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '|O4', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '|O4', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '|O4', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '|O4', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "F\x00{'descr': '|O4', 'fortran_order': False, 'shape': (0,)}              \n"
+    "F\x00{'descr': '|O4', 'fortran_order': False, 'shape': ()}                \n"
+    "F\x00{'descr': '|O4', 'fortran_order': False, 'shape': (15,)}             \n"
+    "F\x00{'descr': '|O4', 'fortran_order': False, 'shape': (3, 5)}            \n"
+    "F\x00{'descr': '|O4', 'fortran_order': True, 'shape': (5, 3)}             \n"
+    "F\x00{'descr': '|O4', 'fortran_order': False, 'shape': (3, 3)}            \n"
+    "v\x00{'descr': [('x', '<i4', (2,)), ('y', '<f8', (2, 2)), ('z', '|u1')],\n 'fortran_order': False,\n 'shape': (2,)}         \n"
+    "\x16\x02{'descr': [('x', '<i4', (2,)),\n           ('Info',\n            [('value', '<c16'),\n             ('y2', '<f8'),\n             ('Info2',\n              [('name', '|S2'),\n               ('value', '<c16', (2,)),\n               ('y3', '<f8', (2,)),\n               ('z3', '<u4', (2,))]),\n             ('name', '|S2'),\n             ('z2', '|b1')]),\n           ('color', '|S2'),\n           ('info', [('Name', '<U8'), ('Value', '<c16')]),\n           ('y', '<f8', (2, 2)),\n           ('z', '|u1')],\n 'fortran_order': False,\n 'shape': (2,)}      \n"
+    "v\x00{'descr': [('x', '>i4', (2,)), ('y', '>f8', (2, 2)), ('z', '|u1')],\n 'fortran_order': False,\n 'shape': (2,)}         \n"
+    "\x16\x02{'descr': [('x', '>i4', (2,)),\n           ('Info',\n            [('value', '>c16'),\n             ('y2', '>f8'),\n             ('Info2',\n              [('name', '|S2'),\n               ('value', '>c16', (2,)),\n               ('y3', '>f8', (2,)),\n               ('z3', '>u4', (2,))]),\n             ('name', '|S2'),\n             ('z2', '|b1')]),\n           ('color', '|S2'),\n           ('info', [('Name', '>U8'), ('Value', '>c16')]),\n           ('y', '>f8', (2, 2)),\n           ('z', '|u1')],\n 'fortran_order': False,\n 'shape': (2,)}      \n"
+'''
+
+
+from cStringIO import StringIO
+import os
+import shutil
+import tempfile
+
+from nose.tools import raises
+
+import numpy as np
+from numpy.testing import assert_array_equal
+
+from numpy.lib import format
+
+
+tempdir = None
+
+# Module-level setup.
+def setup_module():
+    global tempdir
+    tempdir = tempfile.mkdtemp()
+
+def teardown_module():
+    global tempdir
+    if tempdir is not None and os.path.isdir(tempdir):
+        shutil.rmtree(tempdir)
+        tempdir = None
+
+
+# Generate some basic arrays to test with.
+scalars = [
+    np.uint8,
+    np.int8,
+    np.uint16,
+    np.int16,
+    np.uint32,
+    np.int32,
+    np.uint64,
+    np.int64,
+    np.float32,
+    np.float64,
+    np.complex64,
+    np.complex128,
+    object,
+]
+basic_arrays = []
+for scalar in scalars:
+    for endian in '<>':
+        dtype = np.dtype(scalar).newbyteorder(endian)
+        basic = np.arange(15).astype(dtype)
+        basic_arrays.extend([
+            # Empty
+            np.array([], dtype=dtype),
+            # Rank-0
+            np.array(10, dtype=dtype),
+            # 1-D
+            basic,
+            # 2-D C-contiguous
+            basic.reshape((3,5)),
+            # 2-D F-contiguous
+            basic.reshape((3,5)).T,
+            # 2-D non-contiguous
+            basic.reshape((3,5))[::-1,::2],
+        ])
+
+# More complicated record arrays.
+# This is the structure of the table used for plain objects:
+#
+# +-+-+-+
+# |x|y|z|
+# +-+-+-+
+
+# Structure of a plain array description:
+Pdescr = [
+    ('x', 'i4', (2,)),
+    ('y', 'f8', (2, 2)),
+    ('z', 'u1')]
+
+# A plain list of tuples with values for testing:
+PbufferT = [
+    # x     y                  z
+    ([3,2], [[6.,4.],[6.,4.]], 8),
+    ([4,3], [[7.,5.],[7.,5.]], 9),
+    ]
+
+
+# This is the structure of the table used for nested objects (DON'T PANIC!):
+#
+# +-+---------------------------------+-----+----------+-+-+
+# |x|Info                             |color|info      |y|z|
+# | +-----+--+----------------+----+--+     +----+-----+ | |
+# | |value|y2|Info2           |name|z2|     |Name|Value| | |
+# | |     |  +----+-----+--+--+    |  |     |    |     | | |
+# | |     |  |name|value|y3|z3|    |  |     |    |     | | |
+# +-+-----+--+----+-----+--+--+----+--+-----+----+-----+-+-+
+#
+
+# The corresponding nested array description:
+Ndescr = [
+    ('x', 'i4', (2,)),
+    ('Info', [
+        ('value', 'c16'),
+        ('y2', 'f8'),
+        ('Info2', [
+            ('name', 'S2'),
+            ('value', 'c16', (2,)),
+            ('y3', 'f8', (2,)),
+            ('z3', 'u4', (2,))]),
+        ('name', 'S2'),
+        ('z2', 'b1')]),
+    ('color', 'S2'),
+    ('info', [
+        ('Name', 'U8'),
+        ('Value', 'c16')]),
+    ('y', 'f8', (2, 2)),
+    ('z', 'u1')]
+
+NbufferT = [
+    # x     Info                                                color info        y                  z
+    #       value y2 Info2                            name z2         Name Value
+    #                name   value    y3       z3
+    ([3,2], (6j, 6., ('nn', [6j,4j], [6.,4.], [1,2]), 'NN', True), 'cc', ('NN', 6j), [[6.,4.],[6.,4.]], 8),
+    ([4,3], (7j, 7., ('oo', [7j,5j], [7.,5.], [2,1]), 'OO', False), 'dd', ('OO', 7j), [[7.,5.],[7.,5.]], 9),
+    ]
+
+record_arrays = [
+    np.array(PbufferT, dtype=np.dtype(Pdescr).newbyteorder('<')),
+    np.array(NbufferT, dtype=np.dtype(Ndescr).newbyteorder('<')),
+    np.array(PbufferT, dtype=np.dtype(Pdescr).newbyteorder('>')),
+    np.array(NbufferT, dtype=np.dtype(Ndescr).newbyteorder('>')),
+]
+
+def roundtrip(arr):
+    f = StringIO()
+    format.write_array(f, arr)
+    f2 = StringIO(f.getvalue())
+    arr2 = format.read_array(f2)
+    return arr2
+
+def assert_equal(o1, o2):
+    assert o1 == o2
+
+
+def test_roundtrip():
+    for arr in basic_arrays + record_arrays:
+        arr2 = roundtrip(arr)
+        yield assert_array_equal, arr, arr2
+
+def test_memmap_roundtrip():
+    for arr in basic_arrays + record_arrays:
+        if arr.dtype.hasobject:
+            # Skip these since they can't be mmap'ed.
+            continue
+        # Write it out normally and through mmap.
+        nfn = os.path.join(tempdir, 'normal.npy')
+        mfn = os.path.join(tempdir, 'memmap.npy')
+        fp = open(nfn, 'wb')
+        try:
+            format.write_array(fp, arr)
+        finally:
+            fp.close()
+
+        fortran_order = (arr.flags.f_contiguous and not arr.flags.c_contiguous)
+        ma = format.open_memmap(mfn, mode='w+', dtype=arr.dtype,
+            shape=arr.shape, fortran_order=fortran_order)
+        ma[...] = arr
+        del ma
+
+        # Check that both of these files' contents are the same.
+        fp = open(nfn, 'rb')
+        normal_bytes = fp.read()
+        fp.close()
+        fp = open(mfn, 'rb')
+        memmap_bytes = fp.read()
+        fp.close()
+        yield assert_equal, normal_bytes, memmap_bytes
+
+        # Check that reading the file using memmap works.
+        ma = format.open_memmap(nfn, mode='r')
+        yield assert_array_equal, ma, arr
+        del ma
+
+
+def test_write_version_1_0():
+    f = StringIO()
+    arr = np.arange(1)
+    # These should pass.
+    format.write_array(f, arr, version=(1, 0))
+    format.write_array(f, arr)
+
+    # These should all fail.
+    bad_versions = [
+        (1, 1),
+        (0, 0),
+        (0, 1),
+        (2, 0),
+        (2, 2),
+        (255, 255),
+    ]
+    for version in bad_versions:
+        try:
+            format.write_array(f, arr, version=version)
+        except ValueError:
+            pass
+        else:
+            raise AssertionError("we should have raised a ValueError for the bad version %r" % (version,))
+
+
+bad_version_magic = [
+    '\x93NUMPY\x01\x01',
+    '\x93NUMPY\x00\x00',
+    '\x93NUMPY\x00\x01',
+    '\x93NUMPY\x02\x00',
+    '\x93NUMPY\x02\x02',
+    '\x93NUMPY\xff\xff',
+]
+malformed_magic = [
+    '\x92NUMPY\x01\x00',
+    '\x00NUMPY\x01\x00',
+    '\x93numpy\x01\x00',
+    '\x93MATLB\x01\x00',
+    '\x93NUMPY\x01',
+    '\x93NUMPY',
+    '',
+]
+
+def test_read_magic_bad_magic():
+    for magic in malformed_magic:
+        f = StringIO(magic)
+        yield raises(ValueError)(format.read_magic), f
+
+def test_read_version_1_0_bad_magic():
+    for magic in bad_version_magic + malformed_magic:
+        f = StringIO(magic)
+        yield raises(ValueError)(format.read_array), f
+
+