cpython/Lib/test/test_extcall.py

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Get rid of the superstitious "~" in dict hashing's "i = (~hash) & mask". The comment following used to say: /* We use ~hash instead of hash, as degenerate hash functions, such as for ints <sigh>, can have lots of leading zeros. It's not really a performance risk, but better safe than sorry. 12-Dec-00 tim: so ~hash produces lots of leading ones instead -- what's the gain? */ That is, there was never a good reason for doing it. And to the contrary, as explained on Python-Dev last December, it tended to make the *sum* (i + incr) & mask (which is the first table index examined in case of collison) the same "too often" across distinct hashes. Changing to the simpler "i = hash & mask" reduced the number of string-dict collisions (== # number of times we go around the lookup for-loop) from about 6 million to 5 million during a full run of the test suite (these are approximate because the test suite does some random stuff from run to run). The number of collisions in non-string dicts also decreased, but not as dramatically. Note that this may, for a given dict, change the order (wrt previous releases) of entries exposed by .keys(), .values() and .items(). A number of std tests suffered bogus failures as a result. For dicts keyed by small ints, or (less so) by characters, the order is much more likely to be in increasing order of key now; e.g., >>> d = {} >>> for i in range(10): ... d[i] = i ... >>> d {0: 0, 1: 1, 2: 2, 3: 3, 4: 4, 5: 5, 6: 6, 7: 7, 8: 8, 9: 9} >>> Unfortunately. people may latch on to that in small examples and draw a bogus conclusion. test_support.py Moved test_extcall's sortdict() into test_support, made it stronger, and imported sortdict into other std tests that needed it. test_unicode.py Excluced cp875 from the "roundtrip over range(128)" test, because cp875 doesn't have a well-defined inverse for unicode("?", "cp875"). See Python-Dev for excruciating details. Cookie.py Chaged various output functions to sort dicts before building strings from them. test_extcall Fiddled the expected-result file. This remains sensitive to native dict ordering, because, e.g., if there are multiple errors in a keyword-arg dict (and test_extcall sets up many cases like that), the specific error Python complains about first depends on native dict ordering.
2001-05-13 00:19:31 +00:00
from test_support import verify, verbose, TestFailed, sortdict
from UserList import UserList
def f(*a, **k):
print a, sortdict(k)
def g(x, *y, **z):
print x, y, sortdict(z)
def h(j=1, a=2, h=3):
print j, a, h
f()
f(1)
f(1, 2)
f(1, 2, 3)
f(1, 2, 3, *(4, 5))
f(1, 2, 3, *[4, 5])
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f(1, 2, 3, *UserList([4, 5]))
f(1, 2, 3, **{'a':4, 'b':5})
f(1, 2, 3, *(4, 5), **{'a':6, 'b':7})
f(1, 2, 3, x=4, y=5, *(6, 7), **{'a':8, 'b':9})
try:
g()
except TypeError, err:
print "TypeError:", err
else:
print "should raise TypeError: not enough arguments; expected 1, got 0"
try:
g(*())
except TypeError, err:
print "TypeError:", err
else:
print "should raise TypeError: not enough arguments; expected 1, got 0"
try:
g(*(), **{})
except TypeError, err:
print "TypeError:", err
else:
print "should raise TypeError: not enough arguments; expected 1, got 0"
g(1)
g(1, 2)
g(1, 2, 3)
g(1, 2, 3, *(4, 5))
class Nothing: pass
try:
g(*Nothing())
except TypeError, attr:
pass
else:
print "should raise TypeError"
class Nothing:
def __len__(self):
return 5
try:
g(*Nothing())
except TypeError, attr:
pass
else:
print "should raise TypeError"
class Nothing:
def __len__(self):
return 5
def __getitem__(self, i):
if i < 3:
return i
else:
raise IndexError, i
g(*Nothing())
# make sure the function call doesn't stomp on the dictionary?
d = {'a': 1, 'b': 2, 'c': 3}
d2 = d.copy()
verify(d == d2)
g(1, d=4, **d)
print sortdict(d)
print sortdict(d2)
verify(d == d2, "function call modified dictionary")
# what about willful misconduct?
def saboteur(**kw):
kw['x'] = locals() # yields a cyclic kw
return kw
d = {}
kw = saboteur(a=1, **d)
verify(d == {})
# break the cycle
del kw['x']
try:
g(1, 2, 3, **{'x':4, 'y':5})
except TypeError, err:
print err
else:
print "should raise TypeError: keyword parameter redefined"
try:
g(1, 2, 3, a=4, b=5, *(6, 7), **{'a':8, 'b':9})
except TypeError, err:
print err
else:
print "should raise TypeError: keyword parameter redefined"
try:
f(**{1:2})
except TypeError, err:
print err
else:
print "should raise TypeError: keywords must be strings"
try:
h(**{'e': 2})
except TypeError, err:
print err
else:
print "should raise TypeError: unexpected keyword argument: e"
try:
h(*h)
except TypeError, err:
print err
else:
print "should raise TypeError: * argument must be a tuple"
try:
dir(*h)
except TypeError, err:
print err
else:
print "should raise TypeError: * argument must be a tuple"
try:
None(*h)
except TypeError, err:
print err
else:
print "should raise TypeError: * argument must be a tuple"
try:
h(**h)
except TypeError, err:
print err
else:
print "should raise TypeError: ** argument must be a dictionary"
try:
dir(**h)
except TypeError, err:
print err
else:
print "should raise TypeError: ** argument must be a dictionary"
try:
None(**h)
except TypeError, err:
print err
else:
print "should raise TypeError: ** argument must be a dictionary"
try:
dir(b=1,**{'b':1})
except TypeError, err:
print err
else:
print "should raise TypeError: dir() got multiple values for keyword argument 'b'"
def f2(*a, **b):
return a, b
d = {}
for i in range(512):
key = 'k%d' % i
d[key] = i
a, b = f2(1, *(2, 3), **d)
print len(a), len(b), b == d
class Foo:
def method(self, arg1, arg2):
return arg1 + arg2
x = Foo()
print Foo.method(*(x, 1, 2))
print Foo.method(x, *(1, 2))
try:
print Foo.method(*(1, 2, 3))
except TypeError, err:
pass
else:
print 'expected a TypeError for unbound method call'
try:
print Foo.method(1, *(2, 3))
except TypeError, err:
pass
else:
print 'expected a TypeError for unbound method call'
# A PyCFunction that takes only positional parameters should allow an
# empty keyword dictionary to pass without a complaint, but raise a
# TypeError if the dictionary is non-empty.
id(1, **{})
try:
id(1, **{"foo": 1})
except TypeError:
pass
else:
raise TestFailed, 'expected TypeError; no exception raised'
a, b, d, e, v, k = 'A', 'B', 'D', 'E', 'V', 'K'
funcs = []
maxargs = {}
for args in ['', 'a', 'ab']:
for defargs in ['', 'd', 'de']:
for vararg in ['', 'v']:
for kwarg in ['', 'k']:
name = 'z' + args + defargs + vararg + kwarg
arglist = list(args) + map(
lambda x: '%s="%s"' % (x, x), defargs)
if vararg: arglist.append('*' + vararg)
if kwarg: arglist.append('**' + kwarg)
Get rid of the superstitious "~" in dict hashing's "i = (~hash) & mask". The comment following used to say: /* We use ~hash instead of hash, as degenerate hash functions, such as for ints <sigh>, can have lots of leading zeros. It's not really a performance risk, but better safe than sorry. 12-Dec-00 tim: so ~hash produces lots of leading ones instead -- what's the gain? */ That is, there was never a good reason for doing it. And to the contrary, as explained on Python-Dev last December, it tended to make the *sum* (i + incr) & mask (which is the first table index examined in case of collison) the same "too often" across distinct hashes. Changing to the simpler "i = hash & mask" reduced the number of string-dict collisions (== # number of times we go around the lookup for-loop) from about 6 million to 5 million during a full run of the test suite (these are approximate because the test suite does some random stuff from run to run). The number of collisions in non-string dicts also decreased, but not as dramatically. Note that this may, for a given dict, change the order (wrt previous releases) of entries exposed by .keys(), .values() and .items(). A number of std tests suffered bogus failures as a result. For dicts keyed by small ints, or (less so) by characters, the order is much more likely to be in increasing order of key now; e.g., >>> d = {} >>> for i in range(10): ... d[i] = i ... >>> d {0: 0, 1: 1, 2: 2, 3: 3, 4: 4, 5: 5, 6: 6, 7: 7, 8: 8, 9: 9} >>> Unfortunately. people may latch on to that in small examples and draw a bogus conclusion. test_support.py Moved test_extcall's sortdict() into test_support, made it stronger, and imported sortdict into other std tests that needed it. test_unicode.py Excluced cp875 from the "roundtrip over range(128)" test, because cp875 doesn't have a well-defined inverse for unicode("?", "cp875"). See Python-Dev for excruciating details. Cookie.py Chaged various output functions to sort dicts before building strings from them. test_extcall Fiddled the expected-result file. This remains sensitive to native dict ordering, because, e.g., if there are multiple errors in a keyword-arg dict (and test_extcall sets up many cases like that), the specific error Python complains about first depends on native dict ordering.
2001-05-13 00:19:31 +00:00
decl = (('def %s(%s): print "ok %s", a, b, d, e, v, ' +
'type(k) is type ("") and k or sortdict(k)')
% (name, ', '.join(arglist), name))
exec(decl)
func = eval(name)
funcs.append(func)
maxargs[func] = len(args + defargs)
for name in ['za', 'zade', 'zabk', 'zabdv', 'zabdevk']:
func = eval(name)
for args in [(), (1, 2), (1, 2, 3, 4, 5)]:
for kwargs in ['', 'a', 'd', 'ad', 'abde']:
kwdict = {}
for k in kwargs: kwdict[k] = k + k
print func.func_name, args, sortdict(kwdict), '->',
try: apply(func, args, kwdict)
except TypeError, err: print err