lib-python.2.7.test.test_struct.py Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of jython-standalone Show documentation
Show all versions of jython-standalone Show documentation
Jython is an implementation of the high-level, dynamic, object-oriented
language Python written in 100% Pure Java, and seamlessly integrated with
the Java platform. It thus allows you to run Python on any Java platform.
The newest version!
import os
import array
import unittest
import struct
import inspect
from test import test_support as support
from test.test_support import (check_warnings, check_py3k_warnings)
import sys
ISBIGENDIAN = sys.byteorder == "big"
IS32BIT = sys.maxsize == 0x7fffffff
integer_codes = 'b', 'B', 'h', 'H', 'i', 'I', 'l', 'L', 'q', 'Q'
testmod_filename = os.path.splitext(__file__)[0] + '.py'
# Native 'q' packing isn't available on systems that don't have the C
# long long type.
try:
struct.pack('q', 5)
except struct.error:
HAVE_LONG_LONG = False
else:
HAVE_LONG_LONG = True
def string_reverse(s):
return "".join(reversed(s))
def bigendian_to_native(value):
if ISBIGENDIAN:
return value
else:
return string_reverse(value)
class StructTest(unittest.TestCase):
def check_float_coerce(self, format, number):
# SF bug 1530559. struct.pack raises TypeError where it used
# to convert.
with check_warnings((".*integer argument expected, got float",
DeprecationWarning)) as w:
got = struct.pack(format, number)
lineno = inspect.currentframe().f_lineno - 1
self.assertEqual(w.filename, testmod_filename)
self.assertEqual(w.lineno, lineno)
self.assertEqual(len(w.warnings), 1)
expected = struct.pack(format, int(number))
self.assertEqual(got, expected)
def test_isbigendian(self):
self.assertEqual((struct.pack('=i', 1)[0] == chr(0)), ISBIGENDIAN)
def test_consistence(self):
self.assertRaises(struct.error, struct.calcsize, 'Z')
sz = struct.calcsize('i')
self.assertEqual(sz * 3, struct.calcsize('iii'))
fmt = 'cbxxxxxxhhhhiillffd?'
fmt3 = '3c3b18x12h6i6l6f3d3?'
sz = struct.calcsize(fmt)
sz3 = struct.calcsize(fmt3)
self.assertEqual(sz * 3, sz3)
self.assertRaises(struct.error, struct.pack, 'iii', 3)
self.assertRaises(struct.error, struct.pack, 'i', 3, 3, 3)
self.assertRaises((TypeError, struct.error), struct.pack, 'i', 'foo')
self.assertRaises((TypeError, struct.error), struct.pack, 'P', 'foo')
self.assertRaises(struct.error, struct.unpack, 'd', 'flap')
s = struct.pack('ii', 1, 2)
self.assertRaises(struct.error, struct.unpack, 'iii', s)
self.assertRaises(struct.error, struct.unpack, 'i', s)
def test_transitiveness(self):
c = 'a'
b = 1
h = 255
i = 65535
l = 65536
f = 3.1415
d = 3.1415
t = True
for prefix in ('', '@', '<', '>', '=', '!'):
for format in ('xcbhilfd?', 'xcBHILfd?'):
format = prefix + format
s = struct.pack(format, c, b, h, i, l, f, d, t)
cp, bp, hp, ip, lp, fp, dp, tp = struct.unpack(format, s)
self.assertEqual(cp, c)
self.assertEqual(bp, b)
self.assertEqual(hp, h)
self.assertEqual(ip, i)
self.assertEqual(lp, l)
self.assertEqual(int(100 * fp), int(100 * f))
self.assertEqual(int(100 * dp), int(100 * d))
self.assertEqual(tp, t)
def test_new_features(self):
# Test some of the new features in detail
# (format, argument, big-endian result, little-endian result, asymmetric)
tests = [
('c', 'a', 'a', 'a', 0),
('xc', 'a', '\0a', '\0a', 0),
('cx', 'a', 'a\0', 'a\0', 0),
('s', 'a', 'a', 'a', 0),
('0s', 'helloworld', '', '', 1),
('1s', 'helloworld', 'h', 'h', 1),
('9s', 'helloworld', 'helloworl', 'helloworl', 1),
('10s', 'helloworld', 'helloworld', 'helloworld', 0),
('11s', 'helloworld', 'helloworld\0', 'helloworld\0', 1),
('20s', 'helloworld', 'helloworld'+10*'\0', 'helloworld'+10*'\0', 1),
('b', 7, '\7', '\7', 0),
('b', -7, '\371', '\371', 0),
('B', 7, '\7', '\7', 0),
('B', 249, '\371', '\371', 0),
('h', 700, '\002\274', '\274\002', 0),
('h', -700, '\375D', 'D\375', 0),
('H', 700, '\002\274', '\274\002', 0),
('H', 0x10000-700, '\375D', 'D\375', 0),
('i', 70000000, '\004,\035\200', '\200\035,\004', 0),
('i', -70000000, '\373\323\342\200', '\200\342\323\373', 0),
('I', 70000000L, '\004,\035\200', '\200\035,\004', 0),
('I', 0x100000000L-70000000, '\373\323\342\200', '\200\342\323\373', 0),
('l', 70000000, '\004,\035\200', '\200\035,\004', 0),
('l', -70000000, '\373\323\342\200', '\200\342\323\373', 0),
('L', 70000000L, '\004,\035\200', '\200\035,\004', 0),
('L', 0x100000000L-70000000, '\373\323\342\200', '\200\342\323\373', 0),
('f', 2.0, '@\000\000\000', '\000\000\000@', 0),
('d', 2.0, '@\000\000\000\000\000\000\000',
'\000\000\000\000\000\000\000@', 0),
('f', -2.0, '\300\000\000\000', '\000\000\000\300', 0),
('d', -2.0, '\300\000\000\000\000\000\000\000',
'\000\000\000\000\000\000\000\300', 0),
('?', 0, '\0', '\0', 0),
('?', 3, '\1', '\1', 1),
('?', True, '\1', '\1', 0),
('?', [], '\0', '\0', 1),
('?', (1,), '\1', '\1', 1),
]
for fmt, arg, big, lil, asy in tests:
for (xfmt, exp) in [('>'+fmt, big), ('!'+fmt, big), ('<'+fmt, lil),
('='+fmt, ISBIGENDIAN and big or lil)]:
res = struct.pack(xfmt, arg)
self.assertEqual(res, exp)
self.assertEqual(struct.calcsize(xfmt), len(res))
rev = struct.unpack(xfmt, res)[0]
if rev != arg:
self.assertTrue(asy)
def test_calcsize(self):
expected_size = {
'b': 1, 'B': 1,
'h': 2, 'H': 2,
'i': 4, 'I': 4,
'l': 4, 'L': 4,
'q': 8, 'Q': 8,
}
# standard integer sizes
for code in integer_codes:
for byteorder in ('=', '<', '>', '!'):
format = byteorder+code
size = struct.calcsize(format)
self.assertEqual(size, expected_size[code])
# native integer sizes, except 'q' and 'Q'
for format_pair in ('bB', 'hH', 'iI', 'lL'):
for byteorder in ['', '@']:
signed_size = struct.calcsize(byteorder + format_pair[0])
unsigned_size = struct.calcsize(byteorder + format_pair[1])
self.assertEqual(signed_size, unsigned_size)
# bounds for native integer sizes
self.assertEqual(struct.calcsize('b'), 1)
self.assertLessEqual(2, struct.calcsize('h'))
self.assertLessEqual(4, struct.calcsize('l'))
self.assertLessEqual(struct.calcsize('h'), struct.calcsize('i'))
self.assertLessEqual(struct.calcsize('i'), struct.calcsize('l'))
# tests for native 'q' and 'Q' when applicable
if HAVE_LONG_LONG:
self.assertEqual(struct.calcsize('q'), struct.calcsize('Q'))
self.assertLessEqual(8, struct.calcsize('q'))
self.assertLessEqual(struct.calcsize('l'), struct.calcsize('q'))
def test_integers(self):
# Integer tests (bBhHiIlLqQ).
import binascii
class IntTester(unittest.TestCase):
def __init__(self, format):
super(IntTester, self).__init__(methodName='test_one')
self.format = format
self.code = format[-1]
self.direction = format[:-1]
if not self.direction in ('', '@', '=', '<', '>', '!'):
raise ValueError("unrecognized packing direction: %s" %
self.direction)
self.bytesize = struct.calcsize(format)
self.bitsize = self.bytesize * 8
if self.code in tuple('bhilq'):
self.signed = True
self.min_value = -(2L**(self.bitsize-1))
self.max_value = 2L**(self.bitsize-1) - 1
elif self.code in tuple('BHILQ'):
self.signed = False
self.min_value = 0
self.max_value = 2L**self.bitsize - 1
else:
raise ValueError("unrecognized format code: %s" %
self.code)
def test_one(self, x, pack=struct.pack,
unpack=struct.unpack,
unhexlify=binascii.unhexlify):
format = self.format
if self.min_value <= x <= self.max_value:
expected = long(x)
if self.signed and x < 0:
expected += 1L << self.bitsize
self.assertGreaterEqual(expected, 0)
expected = '%x' % expected
if len(expected) & 1:
expected = "0" + expected
expected = unhexlify(expected)
expected = ("\x00" * (self.bytesize - len(expected)) +
expected)
if (self.direction == '<' or
self.direction in ('', '@', '=') and not ISBIGENDIAN):
expected = string_reverse(expected)
self.assertEqual(len(expected), self.bytesize)
# Pack work?
got = pack(format, x)
self.assertEqual(got, expected)
# Unpack work?
retrieved = unpack(format, got)[0]
self.assertEqual(x, retrieved)
# Adding any byte should cause a "too big" error.
self.assertRaises((struct.error, TypeError), unpack, format,
'\x01' + got)
else:
# x is out of range -- verify pack realizes that.
self.assertRaises((OverflowError, ValueError, struct.error),
pack, format, x)
def run(self):
from random import randrange
# Create all interesting powers of 2.
values = []
for exp in range(self.bitsize + 3):
values.append(1L << exp)
# Add some random values.
for i in range(self.bitsize):
val = 0L
for j in range(self.bytesize):
val = (val << 8) | randrange(256)
values.append(val)
# Values absorbed from other tests
values.extend([300, 700000, sys.maxint*4])
# Try all those, and their negations, and +-1 from
# them. Note that this tests all power-of-2
# boundaries in range, and a few out of range, plus
# +-(2**n +- 1).
for base in values:
for val in -base, base:
for incr in -1, 0, 1:
x = val + incr
self.test_one(int(x))
self.test_one(long(x))
# Some error cases.
class NotAnIntNS(object):
def __int__(self):
return 42
def __long__(self):
return 1729L
class NotAnIntOS:
def __int__(self):
return 85
def __long__(self):
return -163L
# Objects with an '__index__' method should be allowed
# to pack as integers. That is assuming the implemented
# '__index__' method returns and 'int' or 'long'.
class Indexable(object):
def __init__(self, value):
self._value = value
def __index__(self):
return self._value
# If the '__index__' method raises a type error, then
# '__int__' should be used with a deprecation warning.
class BadIndex(object):
def __index__(self):
raise TypeError
def __int__(self):
return 42
self.assertRaises((TypeError, struct.error),
struct.pack, self.format,
"a string")
self.assertRaises((TypeError, struct.error),
struct.pack, self.format,
randrange)
with check_warnings(("integer argument expected, "
"got non-integer", DeprecationWarning)):
with self.assertRaises((TypeError, struct.error)):
struct.pack(self.format, 3+42j)
# an attempt to convert a non-integer (with an
# implicit conversion via __int__) should succeed,
# with a DeprecationWarning
for nonint in NotAnIntNS(), NotAnIntOS(), BadIndex():
with check_warnings((".*integer argument expected, got non"
"-integer", DeprecationWarning)) as w:
got = struct.pack(self.format, nonint)
lineno = inspect.currentframe().f_lineno - 1
self.assertEqual(w.filename, testmod_filename)
self.assertEqual(w.lineno, lineno)
self.assertEqual(len(w.warnings), 1)
expected = struct.pack(self.format, int(nonint))
self.assertEqual(got, expected)
# Check for legitimate values from '__index__'.
for obj in (Indexable(0), Indexable(10), Indexable(17),
Indexable(42), Indexable(100), Indexable(127)):
try:
struct.pack(format, obj)
except:
self.fail("integer code pack failed on object "
"with '__index__' method")
# Check for bogus values from '__index__'.
for obj in (Indexable('a'), Indexable(u'b'), Indexable(None),
Indexable({'a': 1}), Indexable([1, 2, 3])):
self.assertRaises((TypeError, struct.error),
struct.pack, self.format,
obj)
byteorders = '', '@', '=', '<', '>', '!'
for code in integer_codes:
for byteorder in byteorders:
if (byteorder in ('', '@') and code in ('q', 'Q') and
not HAVE_LONG_LONG):
continue
format = byteorder+code
t = IntTester(format)
t.run()
def test_p_code(self):
# Test p ("Pascal string") code.
for code, input, expected, expectedback in [
('p','abc', '\x00', ''),
('1p', 'abc', '\x00', ''),
('2p', 'abc', '\x01a', 'a'),
('3p', 'abc', '\x02ab', 'ab'),
('4p', 'abc', '\x03abc', 'abc'),
('5p', 'abc', '\x03abc\x00', 'abc'),
('6p', 'abc', '\x03abc\x00\x00', 'abc'),
('1000p', 'x'*1000, '\xff' + 'x'*999, 'x'*255)]:
got = struct.pack(code, input)
self.assertEqual(got, expected)
(got,) = struct.unpack(code, got)
self.assertEqual(got, expectedback)
def test_705836(self):
# SF bug 705836. "f" had a severe rounding bug, where a carry
# from the low-order discarded bits could propagate into the exponent
# field, causing the result to be wrong by a factor of 2.
import math
for base in range(1, 33):
# smaller <- largest representable float less than base.
delta = 0.5
while base - delta / 2.0 != base:
delta /= 2.0
smaller = base - delta
# Packing this rounds away a solid string of trailing 1 bits.
packed = struct.pack("f", smaller)
self.assertEqual(bigpacked, string_reverse(packed))
unpacked = struct.unpack(">f", bigpacked)[0]
self.assertEqual(base, unpacked)
# Largest finite IEEE single.
big = (1 << 24) - 1
big = math.ldexp(big, 127 - 23)
packed = struct.pack(">f", big)
unpacked = struct.unpack(">f", packed)[0]
self.assertEqual(big, unpacked)
# The same, but tack on a 1 bit so it rounds up to infinity.
big = (1 << 25) - 1
big = math.ldexp(big, 127 - 24)
self.assertRaises(OverflowError, struct.pack, ">f", big)
def test_1530559(self):
# SF bug 1530559. struct.pack raises TypeError where it used to convert.
for endian in ('', '>', '<'):
for fmt in integer_codes:
self.check_float_coerce(endian + fmt, 1.0)
self.check_float_coerce(endian + fmt, 1.5)
def test_unpack_from(self, cls=str):
data = cls('abcd01234')
fmt = '4s'
s = struct.Struct(fmt)
self.assertEqual(s.unpack_from(data), ('abcd',))
self.assertEqual(struct.unpack_from(fmt, data), ('abcd',))
for i in xrange(6):
self.assertEqual(s.unpack_from(data, i), (data[i:i+4],))
self.assertEqual(struct.unpack_from(fmt, data, i), (data[i:i+4],))
for i in xrange(6, len(data) + 1):
self.assertRaises(struct.error, s.unpack_from, data, i)
self.assertRaises(struct.error, struct.unpack_from, fmt, data, i)
def test_pack_into(self):
test_string = 'Reykjavik rocks, eow!'
writable_buf = array.array('c', ' '*100)
fmt = '21s'
s = struct.Struct(fmt)
# Test without offset
s.pack_into(writable_buf, 0, test_string)
from_buf = writable_buf.tostring()[:len(test_string)]
self.assertEqual(from_buf, test_string)
# Test with offset.
s.pack_into(writable_buf, 10, test_string)
from_buf = writable_buf.tostring()[:len(test_string)+10]
self.assertEqual(from_buf, test_string[:10] + test_string)
# Go beyond boundaries.
small_buf = array.array('c', ' '*10)
self.assertRaises((ValueError, struct.error), s.pack_into, small_buf, 0,
test_string)
self.assertRaises((ValueError, struct.error), s.pack_into, small_buf, 2,
test_string)
# Test bogus offset (issue 3694)
sb = small_buf
self.assertRaises((TypeError, struct.error), struct.pack_into, b'', sb,
None)
def test_pack_into_fn(self):
test_string = 'Reykjavik rocks, eow!'
writable_buf = array.array('c', ' '*100)
fmt = '21s'
pack_into = lambda *args: struct.pack_into(fmt, *args)
# Test without offset.
pack_into(writable_buf, 0, test_string)
from_buf = writable_buf.tostring()[:len(test_string)]
self.assertEqual(from_buf, test_string)
# Test with offset.
pack_into(writable_buf, 10, test_string)
from_buf = writable_buf.tostring()[:len(test_string)+10]
self.assertEqual(from_buf, test_string[:10] + test_string)
# Go beyond boundaries.
small_buf = array.array('c', ' '*10)
self.assertRaises((ValueError, struct.error), pack_into, small_buf, 0,
test_string)
self.assertRaises((ValueError, struct.error), pack_into, small_buf, 2,
test_string)
def test_unpack_with_buffer(self):
with check_py3k_warnings(("buffer.. not supported in 3.x",
DeprecationWarning)):
# SF bug 1563759: struct.unpack doesn't support buffer protocol objects
data1 = array.array('B', '\x12\x34\x56\x78')
data2 = buffer('......\x12\x34\x56\x78......', 6, 4)
for data in [data1, data2]:
value, = struct.unpack('>I', data)
self.assertEqual(value, 0x12345678)
self.test_unpack_from(cls=buffer)
def test_bool(self):
class ExplodingBool(object):
def __nonzero__(self):
raise IOError
for prefix in tuple("<>!=")+('',):
false = (), [], [], '', 0
true = [1], 'test', 5, -1, 0xffffffffL+1, 0xffffffff//2
falseFormat = prefix + '?' * len(false)
packedFalse = struct.pack(falseFormat, *false)
unpackedFalse = struct.unpack(falseFormat, packedFalse)
trueFormat = prefix + '?' * len(true)
packedTrue = struct.pack(trueFormat, *true)
unpackedTrue = struct.unpack(trueFormat, packedTrue)
self.assertEqual(len(true), len(unpackedTrue))
self.assertEqual(len(false), len(unpackedFalse))
for t in unpackedFalse:
self.assertFalse(t)
for t in unpackedTrue:
self.assertTrue(t)
packed = struct.pack(prefix+'?', 1)
self.assertEqual(len(packed), struct.calcsize(prefix+'?'))
if len(packed) != 1:
self.assertFalse(prefix, msg='encoded bool is not one byte: %r'
%packed)
self.assertRaises(IOError, struct.pack, prefix + '?',
ExplodingBool())
for c in [b'\x01', b'\x7f', b'\xff', b'\x0f', b'\xf0']:
self.assertTrue(struct.unpack('>?', c)[0])
@unittest.skipUnless(IS32BIT, "Specific to 32bit machines")
def test_crasher(self):
self.assertRaises(MemoryError, struct.pack, "357913941c", "a")
def test_count_overflow(self):
hugecount = '{}b'.format(sys.maxsize+1)
self.assertRaises(struct.error, struct.calcsize, hugecount)
hugecount2 = '{}b{}H'.format(sys.maxsize//2, sys.maxsize//2)
self.assertRaises(struct.error, struct.calcsize, hugecount2)
def check_sizeof(self, format_str, number_of_codes):
# The size of 'PyStructObject'
totalsize = support.calcobjsize('5P')
# The size taken up by the 'formatcode' dynamic array
totalsize += struct.calcsize('3P') * (number_of_codes + 1)
support.check_sizeof(self, struct.Struct(format_str), totalsize)
@support.cpython_only
def test__sizeof__(self):
for code in integer_codes:
self.check_sizeof(code, 1)
self.check_sizeof('BHILfdspP', 9)
self.check_sizeof('B' * 1234, 1234)
self.check_sizeof('fd', 2)
self.check_sizeof('xxxxxxxxxxxxxx', 0)
self.check_sizeof('100H', 100)
self.check_sizeof('187s', 1)
self.check_sizeof('20p', 1)
self.check_sizeof('0s', 1)
self.check_sizeof('0c', 0)
def test_main():
support.run_unittest(StructTest)
if __name__ == '__main__':
test_main()
© 2015 - 2025 Weber Informatics LLC | Privacy Policy