Exercise the new feature set somewhat.

Use TestFailed exception and verbose flag from test_support module.

Lib/test/test_struct.py

+from test_support import TestFailed, verbose
 import struct
 ## import pdb
 
@@ -7,18 +8,19 @@ def simple_err(func, *args):
     except struct.error:
 	pass
     else:
-	print 'expected struct.error not caught'
+	raise TestFailed, "%s%s did not raise struct.error" % (
+	    func.__name__, args)
 ## 	pdb.set_trace()
 
 simple_err(struct.calcsize, 'Q')
 
 sz = struct.calcsize('i')
 if sz * 3 <> struct.calcsize('iii'):
-    print 'inconsistent sizes'
+    raise TestFailed, 'inconsistent sizes'
 
 sz = struct.calcsize('cbhilfd')
 if sz * 3 <> struct.calcsize('3c3b3h3i3l3f3d'):
-    print 'inconsistent sizes'
+    raise TestFailed, 'inconsistent sizes'
 
 simple_err(struct.pack, 'iii', 3)
 simple_err(struct.pack, 'i', 3, 3, 3)
@@ -29,16 +31,77 @@ simple_err(struct.unpack, 'iii', s)
 simple_err(struct.unpack, 'i', s)
 
 c = 'a'
-b = -1
+b = 1
 h = 255
 i = 65535
 l = 65536
 f = 3.1415
 d = 3.1415
 
-s = struct.pack('xcbhilfd', c, b, h, i, l, f, d)
-cp, bp, hp, ip, lp, fp, dp = struct.unpack('xcbhilfd', s)
-if cp <> c or bp <> b or hp <> h or ip <> i or lp <> l or \
-   int(100 * fp) <> int(100 * f) or int(100 * dp) <> int(100 * d):
-   # ^^^ calculate only to two decimal places
-    print 'unpack/pack not transitive'
+for format in ('xcbhilfd', 'xcBHILfd', '@xsbhilfd'):
+    s = struct.pack(format, c, b, h, i, l, f, d)
+    cp, bp, hp, ip, lp, fp, dp = struct.unpack(format, s)
+    if (cp <> c or bp <> b or hp <> h or ip <> i or lp <> l or
+	int(100 * fp) <> int(100 * f) or int(100 * dp) <> int(100 * d)):
+	# ^^^ calculate only to two decimal places
+	raise TestFailed, "unpack/pack not transitive (%s, %s)" % (
+	    str(format), str((cp, bp, hp, ip, lp, fp, dp)))
+
+# Test some of the new features
+
+# (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),
+]
+
+def badpack(fmt, arg, got, exp):
+    return 
+
+def badunpack(fmt, arg, got, exp):
+    return "unpack(%s, %s) -> (%s,) # expected (%s,)" % (
+	`fmt`, `arg`, `got`, `exp`)
+
+isbigendian = struct.pack('=h', 1) == '\0\1'
+
+for fmt, arg, big, lil, asy in tests:
+    if verbose:
+	print `fmt`, `arg`, `big`, `lil`
+    for (xfmt, exp) in [('>'+fmt, big), ('!'+fmt, big), ('<'+fmt, lil),
+			('='+fmt, isbigendian and big or lil)]:
+	res = struct.pack(xfmt, arg)
+	if res != exp:
+	    raise TestFailed, "pack(%s, %s) -> %s # expected %s" % (
+		`fmt`, `arg`, `res`, `exp`)
+	n = struct.calcsize(xfmt)
+	if n != len(res):
+	    raise TestFailed, "calcsize(%s) -> %d # expected %d" % (
+		`xfmt`, n, len(res))
+	rev = struct.unpack(xfmt, res)[0]
+	if rev != arg and not asy:
+	    raise TestFailed, "unpack(%s, %s) -> (%s,) # expected (%s,)" % (
+		`fmt`, `res`, `rev`, `arg`)