Lib/test/test_struct.py

   1 from test_support import TestFailed, verbose
   2 import struct
   3 ## import pdb
   4
   5 def simple_err(func, *args):
   6     try:
   7         apply(func, args)
   8     except struct.error:
   9         pass
  10     else:
  11         raise TestFailed, "%s%s did not raise struct.error" % (
  12             func.__name__, args)
  13 ##      pdb.set_trace()
  14
  15 simple_err(struct.calcsize, 'Q')
  16
  17 sz = struct.calcsize('i')
  18 if sz * 3 <> struct.calcsize('iii'):
  19     raise TestFailed, 'inconsistent sizes'
  20
  21 fmt = 'cbxxxxxxhhhhiillffd'
  22 fmt3 = '3c3b18x12h6i6l6f3d'
  23 sz = struct.calcsize(fmt)
  24 sz3 = struct.calcsize(fmt3)
  25 if sz * 3 <> sz3:
  26     raise TestFailed, 'inconsistent sizes (3*%s -> 3*%d = %d, %s -> %d)' % (
  27         `fmt`, sz, 3*sz, `fmt3`, sz3)
  28
  29 simple_err(struct.pack, 'iii', 3)
  30 simple_err(struct.pack, 'i', 3, 3, 3)
  31 simple_err(struct.pack, 'i', 'foo')
  32 simple_err(struct.unpack, 'd', 'flap')
  33 s = struct.pack('ii', 1, 2)
  34 simple_err(struct.unpack, 'iii', s)
  35 simple_err(struct.unpack, 'i', s)
  36
  37 c = 'a'
  38 b = 1
  39 h = 255
  40 i = 65535
  41 l = 65536
  42 f = 3.1415
  43 d = 3.1415
  44
  45 for prefix in ('', '@', '<', '>', '=', '!'):
  46     for format in ('xcbhilfd', 'xcBHILfd'):
  47         format = prefix + format
  48         if verbose:
  49             print "trying:", format
  50         s = struct.pack(format, c, b, h, i, l, f, d)
  51         cp, bp, hp, ip, lp, fp, dp = struct.unpack(format, s)
  52         if (cp <> c or bp <> b or hp <> h or ip <> i or lp <> l or
  53             int(100 * fp) <> int(100 * f) or int(100 * dp) <> int(100 * d)):
  54             # ^^^ calculate only to two decimal places
  55             raise TestFailed, "unpack/pack not transitive (%s, %s)" % (
  56                 str(format), str((cp, bp, hp, ip, lp, fp, dp)))
  57
  58 # Test some of the new features in detail
  59
  60 # (format, argument, big-endian result, little-endian result, asymmetric)
  61 tests = [
  62     ('c', 'a', 'a', 'a', 0),
  63     ('xc', 'a', '\0a', '\0a', 0),
  64     ('cx', 'a', 'a\0', 'a\0', 0),
  65     ('s', 'a', 'a', 'a', 0),
  66     ('0s', 'helloworld', '', '', 1),
  67     ('1s', 'helloworld', 'h', 'h', 1),
  68     ('9s', 'helloworld', 'helloworl', 'helloworl', 1),
  69     ('10s', 'helloworld', 'helloworld', 'helloworld', 0),
  70     ('11s', 'helloworld', 'helloworld\0', 'helloworld\0', 1),
  71     ('20s', 'helloworld', 'helloworld'+10*'\0', 'helloworld'+10*'\0', 1),
  72     ('b', 7, '\7', '\7', 0),
  73     ('b', -7, '\371', '\371', 0),
  74     ('B', 7, '\7', '\7', 0),
  75     ('B', 249, '\371', '\371', 0),
  76     ('h', 700, '\002\274', '\274\002', 0),
  77     ('h', -700, '\375D', 'D\375', 0),
  78     ('H', 700, '\002\274', '\274\002', 0),
  79     ('H', 0x10000-700, '\375D', 'D\375', 0),
  80     ('i', 70000000, '\004,\035\200', '\200\035,\004', 0),
  81     ('i', -70000000, '\373\323\342\200', '\200\342\323\373', 0),
  82     ('I', 70000000L, '\004,\035\200', '\200\035,\004', 0),
  83     ('I', 0x100000000L-70000000, '\373\323\342\200', '\200\342\323\373', 0),
  84     ('l', 70000000, '\004,\035\200', '\200\035,\004', 0),
  85     ('l', -70000000, '\373\323\342\200', '\200\342\323\373', 0),
  86     ('L', 70000000L, '\004,\035\200', '\200\035,\004', 0),
  87     ('L', 0x100000000L-70000000, '\373\323\342\200', '\200\342\323\373', 0),
  88     ('f', 2.0, '@\000\000\000', '\000\000\000@', 0),
  89     ('d', 2.0, '@\000\000\000\000\000\000\000',
  90                '\000\000\000\000\000\000\000@', 0),
  91     ('f', -2.0, '\300\000\000\000', '\000\000\000\300', 0),
  92     ('d', -2.0, '\300\000\000\000\000\000\000\000',
  93                '\000\000\000\000\000\000\000\300', 0),
  94 ]
  95
  96 def badpack(fmt, arg, got, exp):
  97     return
  98
  99 def badunpack(fmt, arg, got, exp):
 100     return "unpack(%s, %s) -> (%s,) # expected (%s,)" % (
 101         `fmt`, `arg`, `got`, `exp`)
 102
 103 isbigendian = struct.pack('=h', 1) == '\0\1'
 104
 105 for fmt, arg, big, lil, asy in tests:
 106     if verbose:
 107         print `fmt`, `arg`, `big`, `lil`
 108     for (xfmt, exp) in [('>'+fmt, big), ('!'+fmt, big), ('<'+fmt, lil),
 109                         ('='+fmt, isbigendian and big or lil)]:
 110         res = struct.pack(xfmt, arg)
 111         if res != exp:
 112             raise TestFailed, "pack(%s, %s) -> %s # expected %s" % (
 113                 `fmt`, `arg`, `res`, `exp`)
 114         n = struct.calcsize(xfmt)
 115         if n != len(res):
 116             raise TestFailed, "calcsize(%s) -> %d # expected %d" % (
 117                 `xfmt`, n, len(res))
 118         rev = struct.unpack(xfmt, res)[0]
 119         if rev != arg and not asy:
 120             raise TestFailed, "unpack(%s, %s) -> (%s,) # expected (%s,)" % (
 121                 `fmt`, `res`, `rev`, `arg`)