import abc import collections from itertools import permutations import pickle from random import choice import sys from test import support import unittest from weakref import proxy try: import threading except ImportError: threading = None import functools py_functools = support.import_fresh_module('functools', blocked=['_functools']) c_functools = support.import_fresh_module('functools', fresh=['_functools']) decimal = support.import_fresh_module('decimal', fresh=['_decimal']) def capture(*args, **kw): """capture all positional and keyword arguments""" return args, kw def signature(part): """ return the signature of a partial object """ return (part.func, part.args, part.keywords, part.__dict__) class TestPartial: def test_basic_examples(self): p = self.partial(capture, 1, 2, a=10, b=20) self.assertTrue(callable(p)) self.assertEqual(p(3, 4, b=30, c=40), ((1, 2, 3, 4), dict(a=10, b=30, c=40))) p = self.partial(map, lambda x: x*10) self.assertEqual(list(p([1,2,3,4])), [10, 20, 30, 40]) def test_attributes(self): p = self.partial(capture, 1, 2, a=10, b=20) # attributes should be readable self.assertEqual(p.func, capture) self.assertEqual(p.args, (1, 2)) self.assertEqual(p.keywords, dict(a=10, b=20)) def test_argument_checking(self): self.assertRaises(TypeError, self.partial) # need at least a func arg try: self.partial(2)() except TypeError: pass else: self.fail('First arg not checked for callability') def test_protection_of_callers_dict_argument(self): # a caller's dictionary should not be altered by partial def func(a=10, b=20): return a d = {'a':3} p = self.partial(func, a=5) self.assertEqual(p(**d), 3) self.assertEqual(d, {'a':3}) p(b=7) self.assertEqual(d, {'a':3}) def test_arg_combinations(self): # exercise special code paths for zero args in either partial # object or the caller p = self.partial(capture) self.assertEqual(p(), ((), {})) self.assertEqual(p(1,2), ((1,2), {})) p = self.partial(capture, 1, 2) self.assertEqual(p(), ((1,2), {})) self.assertEqual(p(3,4), ((1,2,3,4), {})) def test_kw_combinations(self): # exercise special code paths for no keyword args in # either the partial object or the caller p = self.partial(capture) self.assertEqual(p.keywords, {}) self.assertEqual(p(), ((), {})) self.assertEqual(p(a=1), ((), {'a':1})) p = self.partial(capture, a=1) self.assertEqual(p.keywords, {'a':1}) self.assertEqual(p(), ((), {'a':1})) self.assertEqual(p(b=2), ((), {'a':1, 'b':2})) # keyword args in the call override those in the partial object self.assertEqual(p(a=3, b=2), ((), {'a':3, 'b':2})) def test_positional(self): # make sure positional arguments are captured correctly for args in [(), (0,), (0,1), (0,1,2), (0,1,2,3)]: p = self.partial(capture, *args) expected = args + ('x',) got, empty = p('x') self.assertTrue(expected == got and empty == {}) def test_keyword(self): # make sure keyword arguments are captured correctly for a in ['a', 0, None, 3.5]: p = self.partial(capture, a=a) expected = {'a':a,'x':None} empty, got = p(x=None) self.assertTrue(expected == got and empty == ()) def test_no_side_effects(self): # make sure there are no side effects that affect subsequent calls p = self.partial(capture, 0, a=1) args1, kw1 = p(1, b=2) self.assertTrue(args1 == (0,1) and kw1 == {'a':1,'b':2}) args2, kw2 = p() self.assertTrue(args2 == (0,) and kw2 == {'a':1}) def test_error_propagation(self): def f(x, y): x / y self.assertRaises(ZeroDivisionError, self.partial(f, 1, 0)) self.assertRaises(ZeroDivisionError, self.partial(f, 1), 0) self.assertRaises(ZeroDivisionError, self.partial(f), 1, 0) self.assertRaises(ZeroDivisionError, self.partial(f, y=0), 1) def test_weakref(self): f = self.partial(int, base=16) p = proxy(f) self.assertEqual(f.func, p.func) f = None self.assertRaises(ReferenceError, getattr, p, 'func') def test_with_bound_and_unbound_methods(self): data = list(map(str, range(10))) join = self.partial(str.join, '') self.assertEqual(join(data), '0123456789') join = self.partial(''.join) self.assertEqual(join(data), '0123456789') def test_nested_optimization(self): partial = self.partial inner = partial(signature, 'asdf') nested = partial(inner, bar=True) flat = partial(signature, 'asdf', bar=True) self.assertEqual(signature(nested), signature(flat)) def test_nested_partial_with_attribute(self): # see issue 25137 partial = self.partial def foo(bar): return bar p = partial(foo, 'first') p2 = partial(p, 'second') p2.new_attr = 'spam' self.assertEqual(p2.new_attr, 'spam') @unittest.skipUnless(c_functools, 'requires the C _functools module') class TestPartialC(TestPartial, unittest.TestCase): if c_functools: partial = c_functools.partial def test_attributes_unwritable(self): # attributes should not be writable p = self.partial(capture, 1, 2, a=10, b=20) self.assertRaises(AttributeError, setattr, p, 'func', map) self.assertRaises(AttributeError, setattr, p, 'args', (1, 2)) self.assertRaises(AttributeError, setattr, p, 'keywords', dict(a=1, b=2)) p = self.partial(hex) try: del p.__dict__ except TypeError: pass else: self.fail('partial object allowed __dict__ to be deleted') def test_repr(self): args = (object(), object()) args_repr = ', '.join(repr(a) for a in args) kwargs = {'a': object(), 'b': object()} kwargs_reprs = ['a={a!r}, b={b!r}'.format_map(kwargs), 'b={b!r}, a={a!r}'.format_map(kwargs)] if self.partial is c_functools.partial: name = 'functools.partial' else: name = self.partial.__name__ f = self.partial(capture) self.assertEqual('{}({!r})'.format(name, capture), repr(f)) f = self.partial(capture, *args) self.assertEqual('{}({!r}, {})'.format(name, capture, args_repr), repr(f)) f = self.partial(capture, **kwargs) self.assertIn(repr(f), ['{}({!r}, {})'.format(name, capture, kwargs_repr) for kwargs_repr in kwargs_reprs]) f = self.partial(capture, *args, **kwargs) self.assertIn(repr(f), ['{}({!r}, {}, {})'.format(name, capture, args_repr, kwargs_repr) for kwargs_repr in kwargs_reprs]) def test_pickle(self): f = self.partial(signature, 'asdf', bar=True) f.add_something_to__dict__ = True for proto in range(pickle.HIGHEST_PROTOCOL + 1): f_copy = pickle.loads(pickle.dumps(f, proto)) self.assertEqual(signature(f), signature(f_copy)) # Issue 6083: Reference counting bug def test_setstate_refcount(self): class BadSequence: def __len__(self): return 4 def __getitem__(self, key): if key == 0: return max elif key == 1: return tuple(range(1000000)) elif key in (2, 3): return {} raise IndexError f = self.partial(object) self.assertRaisesRegex(SystemError, "new style getargs format but argument is not a tuple", f.__setstate__, BadSequence()) class TestPartialPy(TestPartial, unittest.TestCase): partial = staticmethod(py_functools.partial) if c_functools: class PartialSubclass(c_functools.partial): pass @unittest.skipUnless(c_functools, 'requires the C _functools module') class TestPartialCSubclass(TestPartialC): if c_functools: partial = PartialSubclass # partial subclasses are not optimized for nested calls test_nested_optimization = None class TestPartialMethod(unittest.TestCase): class A(object): nothing = functools.partialmethod(capture) positional = functools.partialmethod(capture, 1) keywords = functools.partialmethod(capture, a=2) both = functools.partialmethod(capture, 3, b=4) nested = functools.partialmethod(positional, 5) over_partial = functools.partialmethod(functools.partial(capture, c=6), 7) static = functools.partialmethod(staticmethod(capture), 8) cls = functools.partialmethod(classmethod(capture), d=9) a = A() def test_arg_combinations(self): self.assertEqual(self.a.nothing(), ((self.a,), {})) self.assertEqual(self.a.nothing(5), ((self.a, 5), {})) self.assertEqual(self.a.nothing(c=6), ((self.a,), {'c': 6})) self.assertEqual(self.a.nothing(5, c=6), ((self.a, 5), {'c': 6})) self.assertEqual(self.a.positional(), ((self.a, 1), {})) self.assertEqual(self.a.positional(5), ((self.a, 1, 5), {})) self.assertEqual(self.a.positional(c=6), ((self.a, 1), {'c': 6})) self.assertEqual(self.a.positional(5, c=6), ((self.a, 1, 5), {'c': 6})) self.assertEqual(self.a.keywords(), ((self.a,), {'a': 2})) self.assertEqual(self.a.keywords(5), ((self.a, 5), {'a': 2})) self.assertEqual(self.a.keywords(c=6), ((self.a,), {'a': 2, 'c': 6})) self.assertEqual(self.a.keywords(5, c=6), ((self.a, 5), {'a': 2, 'c': 6})) self.assertEqual(self.a.both(), ((self.a, 3), {'b': 4})) self.assertEqual(self.a.both(5), ((self.a, 3, 5), {'b': 4})) self.assertEqual(self.a.both(c=6), ((self.a, 3), {'b': 4, 'c': 6})) self.assertEqual(self.a.both(5, c=6), ((self.a, 3, 5), {'b': 4, 'c': 6})) self.assertEqual(self.A.both(self.a, 5, c=6), ((self.a, 3, 5), {'b': 4, 'c': 6})) def test_nested(self): self.assertEqual(self.a.nested(), ((self.a, 1, 5), {})) self.assertEqual(self.a.nested(6), ((self.a, 1, 5, 6), {})) self.assertEqual(self.a.nested(d=7), ((self.a, 1, 5), {'d': 7})) self.assertEqual(self.a.nested(6, d=7), ((self.a, 1, 5, 6), {'d': 7})) self.assertEqual(self.A.nested(self.a, 6, d=7), ((self.a, 1, 5, 6), {'d': 7})) def test_over_partial(self): self.assertEqual(self.a.over_partial(), ((self.a, 7), {'c': 6})) self.assertEqual(self.a.over_partial(5), ((self.a, 7, 5), {'c': 6})) self.assertEqual(self.a.over_partial(d=8), ((self.a, 7), {'c': 6, 'd': 8})) self.assertEqual(self.a.over_partial(5, d=8), ((self.a, 7, 5), {'c': 6, 'd': 8})) self.assertEqual(self.A.over_partial(self.a, 5, d=8), ((self.a, 7, 5), {'c': 6, 'd': 8})) def test_bound_method_introspection(self): obj = self.a self.assertIs(obj.both.__self__, obj) self.assertIs(obj.nested.__self__, obj) self.assertIs(obj.over_partial.__self__, obj) self.assertIs(obj.cls.__self__, self.A) self.assertIs(self.A.cls.__self__, self.A) def test_unbound_method_retrieval(self): obj = self.A self.assertFalse(hasattr(obj.both, "__self__")) self.assertFalse(hasattr(obj.nested, "__self__")) self.assertFalse(hasattr(obj.over_partial, "__self__")) self.assertFalse(hasattr(obj.static, "__self__")) self.assertFalse(hasattr(self.a.static, "__self__")) def test_descriptors(self): for obj in [self.A, self.a]: with self.subTest(obj=obj): self.assertEqual(obj.static(), ((8,), {})) self.assertEqual(obj.static(5), ((8, 5), {})) self.assertEqual(obj.static(d=8), ((8,), {'d': 8})) self.assertEqual(obj.static(5, d=8), ((8, 5), {'d': 8})) self.assertEqual(obj.cls(), ((self.A,), {'d': 9})) self.assertEqual(obj.cls(5), ((self.A, 5), {'d': 9})) self.assertEqual(obj.cls(c=8), ((self.A,), {'c': 8, 'd': 9})) self.assertEqual(obj.cls(5, c=8), ((self.A, 5), {'c': 8, 'd': 9})) def test_overriding_keywords(self): self.assertEqual(self.a.keywords(a=3), ((self.a,), {'a': 3})) self.assertEqual(self.A.keywords(self.a, a=3), ((self.a,), {'a': 3})) def test_invalid_args(self): with self.assertRaises(TypeError): class B(object): method = functools.partialmethod(None, 1) def test_repr(self): self.assertEqual(repr(vars(self.A)['both']), 'functools.partialmethod({}, 3, b=4)'.format(capture)) def test_abstract(self): class Abstract(abc.ABCMeta): @abc.abstractmethod def add(self, x, y): pass add5 = functools.partialmethod(add, 5) self.assertTrue(Abstract.add.__isabstractmethod__) self.assertTrue(Abstract.add5.__isabstractmethod__) for func in [self.A.static, self.A.cls, self.A.over_partial, self.A.nested, self.A.both]: self.assertFalse(getattr(func, '__isabstractmethod__', False)) class TestUpdateWrapper(unittest.TestCase): def check_wrapper(self, wrapper, wrapped, assigned=functools.WRAPPER_ASSIGNMENTS, updated=functools.WRAPPER_UPDATES): # Check attributes were assigned for name in assigned: self.assertIs(getattr(wrapper, name), getattr(wrapped, name)) # Check attributes were updated for name in updated: wrapper_attr = getattr(wrapper, name) wrapped_attr = getattr(wrapped, name) for key in wrapped_attr: if name == "__dict__" and key == "__wrapped__": # __wrapped__ is overwritten by the update code continue self.assertIs(wrapped_attr[key], wrapper_attr[key]) # Check __wrapped__ self.assertIs(wrapper.__wrapped__, wrapped) def _default_update(self): def f(a:'This is a new annotation'): """This is a test""" pass f.attr = 'This is also a test' f.__wrapped__ = "This is a bald faced lie" def wrapper(b:'This is the prior annotation'): pass functools.update_wrapper(wrapper, f) return wrapper, f def test_default_update(self): wrapper, f = self._default_update() self.check_wrapper(wrapper, f) self.assertIs(wrapper.__wrapped__, f) self.assertEqual(wrapper.__name__, 'f') self.assertEqual(wrapper.__qualname__, f.__qualname__) self.assertEqual(wrapper.attr, 'This is also a test') self.assertEqual(wrapper.__annotations__['a'], 'This is a new annotation') self.assertNotIn('b', wrapper.__annotations__) @unittest.skipIf(sys.flags.optimize >= 2, "Docstrings are omitted with -O2 and above") def test_default_update_doc(self): wrapper, f = self._default_update() self.assertEqual(wrapper.__doc__, 'This is a test') def test_no_update(self): def f(): """This is a test""" pass f.attr = 'This is also a test' def wrapper(): pass functools.update_wrapper(wrapper, f, (), ()) self.check_wrapper(wrapper, f, (), ()) self.assertEqual(wrapper.__name__, 'wrapper') self.assertNotEqual(wrapper.__qualname__, f.__qualname__) self.assertEqual(wrapper.__doc__, None) self.assertEqual(wrapper.__annotations__, {}) self.assertFalse(hasattr(wrapper, 'attr')) def test_selective_update(self): def f(): pass f.attr = 'This is a different test' f.dict_attr = dict(a=1, b=2, c=3) def wrapper(): pass wrapper.dict_attr = {} assign = ('attr',) update = ('dict_attr',) functools.update_wrapper(wrapper, f, assign, update) self.check_wrapper(wrapper, f, assign, update) self.assertEqual(wrapper.__name__, 'wrapper') self.assertNotEqual(wrapper.__qualname__, f.__qualname__) self.assertEqual(wrapper.__doc__, None) self.assertEqual(wrapper.attr, 'This is a different test') self.assertEqual(wrapper.dict_attr, f.dict_attr) def test_missing_attributes(self): def f(): pass def wrapper(): pass wrapper.dict_attr = {} assign = ('attr',) update = ('dict_attr',) # Missing attributes on wrapped object are ignored functools.update_wrapper(wrapper, f, assign, update) self.assertNotIn('attr', wrapper.__dict__) self.assertEqual(wrapper.dict_attr, {}) # Wrapper must have expected attributes for updating del wrapper.dict_attr with self.assertRaises(AttributeError): functools.update_wrapper(wrapper, f, assign, update) wrapper.dict_attr = 1 with self.assertRaises(AttributeError): functools.update_wrapper(wrapper, f, assign, update) @support.requires_docstrings @unittest.skipIf(sys.flags.optimize >= 2, "Docstrings are omitted with -O2 and above") def test_builtin_update(self): # Test for bug #1576241 def wrapper(): pass functools.update_wrapper(wrapper, max) self.assertEqual(wrapper.__name__, 'max') self.assertTrue(wrapper.__doc__.startswith('max(')) self.assertEqual(wrapper.__annotations__, {}) class TestWraps(TestUpdateWrapper): def _default_update(self): def f(): """This is a test""" pass f.attr = 'This is also a test' f.__wrapped__ = "This is still a bald faced lie" @functools.wraps(f) def wrapper(): pass return wrapper, f def test_default_update(self): wrapper, f = self._default_update() self.check_wrapper(wrapper, f) self.assertEqual(wrapper.__name__, 'f') self.assertEqual(wrapper.__qualname__, f.__qualname__) self.assertEqual(wrapper.attr, 'This is also a test') @unittest.skipIf(sys.flags.optimize >= 2, "Docstrings are omitted with -O2 and above") def test_default_update_doc(self): wrapper, _ = self._default_update() self.assertEqual(wrapper.__doc__, 'This is a test') def test_no_update(self): def f(): """This is a test""" pass f.attr = 'This is also a test' @functools.wraps(f, (), ()) def wrapper(): pass self.check_wrapper(wrapper, f, (), ()) self.assertEqual(wrapper.__name__, 'wrapper') self.assertNotEqual(wrapper.__qualname__, f.__qualname__) self.assertEqual(wrapper.__doc__, None) self.assertFalse(hasattr(wrapper, 'attr')) def test_selective_update(self): def f(): pass f.attr = 'This is a different test' f.dict_attr = dict(a=1, b=2, c=3) def add_dict_attr(f): f.dict_attr = {} return f assign = ('attr',) update = ('dict_attr',) @functools.wraps(f, assign, update) @add_dict_attr def wrapper(): pass self.check_wrapper(wrapper, f, assign, update) self.assertEqual(wrapper.__name__, 'wrapper') self.assertNotEqual(wrapper.__qualname__, f.__qualname__) self.assertEqual(wrapper.__doc__, None) self.assertEqual(wrapper.attr, 'This is a different test') self.assertEqual(wrapper.dict_attr, f.dict_attr) class TestReduce(unittest.TestCase): func = functools.reduce def test_reduce(self): class Squares: def __init__(self, max): self.max = max self.sofar = [] def __len__(self): return len(self.sofar) def __getitem__(self, i): if not 0 <= i < self.max: raise IndexError n = len(self.sofar) while n <= i: self.sofar.append(n*n) n += 1 return self.sofar[i] def add(x, y): return x + y self.assertEqual(self.func(add, ['a', 'b', 'c'], ''), 'abc') self.assertEqual( self.func(add, [['a', 'c'], [], ['d', 'w']], []), ['a','c','d','w'] ) self.assertEqual(self.func(lambda x, y: x*y, range(2,8), 1), 5040) self.assertEqual( self.func(lambda x, y: x*y, range(2,21), 1), 2432902008176640000 ) self.assertEqual(self.func(add, Squares(10)), 285) self.assertEqual(self.func(add, Squares(10), 0), 285) self.assertEqual(self.func(add, Squares(0), 0), 0) self.assertRaises(TypeError, self.func) self.assertRaises(TypeError, self.func, 42, 42) self.assertRaises(TypeError, self.func, 42, 42, 42) self.assertEqual(self.func(42, "1"), "1") # func is never called with one item self.assertEqual(self.func(42, "", "1"), "1") # func is never called with one item self.assertRaises(TypeError, self.func, 42, (42, 42)) self.assertRaises(TypeError, self.func, add, []) # arg 2 must not be empty sequence with no initial value self.assertRaises(TypeError, self.func, add, "") self.assertRaises(TypeError, self.func, add, ()) self.assertRaises(TypeError, self.func, add, object()) class TestFailingIter: def __iter__(self): raise RuntimeError self.assertRaises(RuntimeError, self.func, add, TestFailingIter()) self.assertEqual(self.func(add, [], None), None) self.assertEqual(self.func(add, [], 42), 42) class BadSeq: def __getitem__(self, index): raise ValueError self.assertRaises(ValueError, self.func, 42, BadSeq()) # Test reduce()'s use of iterators. def test_iterator_usage(self): class SequenceClass: def __init__(self, n): self.n = n def __getitem__(self, i): if 0 <= i < self.n: return i else: raise IndexError from operator import add self.assertEqual(self.func(add, SequenceClass(5)), 10) self.assertEqual(self.func(add, SequenceClass(5), 42), 52) self.assertRaises(TypeError, self.func, add, SequenceClass(0)) self.assertEqual(self.func(add, SequenceClass(0), 42), 42) self.assertEqual(self.func(add, SequenceClass(1)), 0) self.assertEqual(self.func(add, SequenceClass(1), 42), 42) d = {"one": 1, "two": 2, "three": 3} self.assertEqual(self.func(add, d), "".join(d.keys())) class TestCmpToKey: def test_cmp_to_key(self): def cmp1(x, y): return (x > y) - (x < y) key = self.cmp_to_key(cmp1) self.assertEqual(key(3), key(3)) self.assertGreater(key(3), key(1)) self.assertGreaterEqual(key(3), key(3)) def cmp2(x, y): return int(x) - int(y) key = self.cmp_to_key(cmp2) self.assertEqual(key(4.0), key('4')) self.assertLess(key(2), key('35')) self.assertLessEqual(key(2), key('35')) self.assertNotEqual(key(2), key('35')) def test_cmp_to_key_arguments(self): def cmp1(x, y): return (x > y) - (x < y) key = self.cmp_to_key(mycmp=cmp1) self.assertEqual(key(obj=3), key(obj=3)) self.assertGreater(key(obj=3), key(obj=1)) with self.assertRaises((TypeError, AttributeError)): key(3) > 1 # rhs is not a K object with self.assertRaises((TypeError, AttributeError)): 1 < key(3) # lhs is not a K object with self.assertRaises(TypeError): key = self.cmp_to_key() # too few args with self.assertRaises(TypeError): key = self.cmp_to_key(cmp1, None) # too many args key = self.cmp_to_key(cmp1) with self.assertRaises(TypeError): key() # too few args with self.assertRaises(TypeError): key(None, None) # too many args def test_bad_cmp(self): def cmp1(x, y): raise ZeroDivisionError key = self.cmp_to_key(cmp1) with self.assertRaises(ZeroDivisionError): key(3) > key(1) class BadCmp: def __lt__(self, other): raise ZeroDivisionError def cmp1(x, y): return BadCmp() with self.assertRaises(ZeroDivisionError): key(3) > key(1) def test_obj_field(self): def cmp1(x, y): return (x > y) - (x < y) key = self.cmp_to_key(mycmp=cmp1) self.assertEqual(key(50).obj, 50) def test_sort_int(self): def mycmp(x, y): return y - x self.assertEqual(sorted(range(5), key=self.cmp_to_key(mycmp)), [4, 3, 2, 1, 0]) def test_sort_int_str(self): def mycmp(x, y): x, y = int(x), int(y) return (x > y) - (x < y) values = [5, '3', 7, 2, '0', '1', 4, '10', 1] values = sorted(values, key=self.cmp_to_key(mycmp)) self.assertEqual([int(value) for value in values], [0, 1, 1, 2, 3, 4, 5, 7, 10]) def test_hash(self): def mycmp(x, y): return y - x key = self.cmp_to_key(mycmp) k = key(10) self.assertRaises(TypeError, hash, k) self.assertNotIsInstance(k, collections.Hashable) @unittest.skipUnless(c_functools, 'requires the C _functools module') class TestCmpToKeyC(TestCmpToKey, unittest.TestCase): if c_functools: cmp_to_key = c_functools.cmp_to_key class TestCmpToKeyPy(TestCmpToKey, unittest.TestCase): cmp_to_key = staticmethod(py_functools.cmp_to_key) class TestTotalOrdering(unittest.TestCase): def test_total_ordering_lt(self): @functools.total_ordering class A: def __init__(self, value): self.value = value def __lt__(self, other): return self.value < other.value def __eq__(self, other): return self.value == other.value self.assertTrue(A(1) < A(2)) self.assertTrue(A(2) > A(1)) self.assertTrue(A(1) <= A(2)) self.assertTrue(A(2) >= A(1)) self.assertTrue(A(2) <= A(2)) self.assertTrue(A(2) >= A(2)) self.assertFalse(A(1) > A(2)) def test_total_ordering_le(self): @functools.total_ordering class A: def __init__(self, value): self.value = value def __le__(self, other): return self.value <= other.value def __eq__(self, other): return self.value == other.value self.assertTrue(A(1) < A(2)) self.assertTrue(A(2) > A(1)) self.assertTrue(A(1) <= A(2)) self.assertTrue(A(2) >= A(1)) self.assertTrue(A(2) <= A(2)) self.assertTrue(A(2) >= A(2)) self.assertFalse(A(1) >= A(2)) def test_total_ordering_gt(self): @functools.total_ordering class A: def __init__(self, value): self.value = value def __gt__(self, other): return self.value > other.value def __eq__(self, other): return self.value == other.value self.assertTrue(A(1) < A(2)) self.assertTrue(A(2) > A(1)) self.assertTrue(A(1) <= A(2)) self.assertTrue(A(2) >= A(1)) self.assertTrue(A(2) <= A(2)) self.assertTrue(A(2) >= A(2)) self.assertFalse(A(2) < A(1)) def test_total_ordering_ge(self): @functools.total_ordering class A: def __init__(self, value): self.value = value def __ge__(self, other): return self.value >= other.value def __eq__(self, other): return self.value == other.value self.assertTrue(A(1) < A(2)) self.assertTrue(A(2) > A(1)) self.assertTrue(A(1) <= A(2)) self.assertTrue(A(2) >= A(1)) self.assertTrue(A(2) <= A(2)) self.assertTrue(A(2) >= A(2)) self.assertFalse(A(2) <= A(1)) def test_total_ordering_no_overwrite(self): # new methods should not overwrite existing @functools.total_ordering class A(int): pass self.assertTrue(A(1) < A(2)) self.assertTrue(A(2) > A(1)) self.assertTrue(A(1) <= A(2)) self.assertTrue(A(2) >= A(1)) self.assertTrue(A(2) <= A(2)) self.assertTrue(A(2) >= A(2)) def test_no_operations_defined(self): with self.assertRaises(ValueError): @functools.total_ordering class A: pass def test_type_error_when_not_implemented(self): # bug 10042; ensure stack overflow does not occur # when decorated types return NotImplemented @functools.total_ordering class ImplementsLessThan: def __init__(self, value): self.value = value def __eq__(self, other): if isinstance(other, ImplementsLessThan): return self.value == other.value return False def __lt__(self, other): if isinstance(other, ImplementsLessThan): return self.value < other.value return NotImplemented @functools.total_ordering class ImplementsGreaterThan: def __init__(self, value): self.value = value def __eq__(self, other): if isinstance(other, ImplementsGreaterThan): return self.value == other.value return False def __gt__(self, other): if isinstance(other, ImplementsGreaterThan): return self.value > other.value return NotImplemented @functools.total_ordering class ImplementsLessThanEqualTo: def __init__(self, value): self.value = value def __eq__(self, other): if isinstance(other, ImplementsLessThanEqualTo): return self.value == other.value return False def __le__(self, other): if isinstance(other, ImplementsLessThanEqualTo): return self.value <= other.value return NotImplemented @functools.total_ordering class ImplementsGreaterThanEqualTo: def __init__(self, value): self.value = value def __eq__(self, other): if isinstance(other, ImplementsGreaterThanEqualTo): return self.value == other.value return False def __ge__(self, other): if isinstance(other, ImplementsGreaterThanEqualTo): return self.value >= other.value return NotImplemented @functools.total_ordering class ComparatorNotImplemented: def __init__(self, value): self.value = value def __eq__(self, other): if isinstance(other, ComparatorNotImplemented): return self.value == other.value return False def __lt__(self, other): return NotImplemented with self.subTest("LT < 1"), self.assertRaises(TypeError): ImplementsLessThan(-1) < 1 with self.subTest("LT < LE"), self.assertRaises(TypeError): ImplementsLessThan(0) < ImplementsLessThanEqualTo(0) with self.subTest("LT < GT"), self.assertRaises(TypeError): ImplementsLessThan(1) < ImplementsGreaterThan(1) with self.subTest("LE <= LT"), self.assertRaises(TypeError): ImplementsLessThanEqualTo(2) <= ImplementsLessThan(2) with self.subTest("LE <= GE"), self.assertRaises(TypeError): ImplementsLessThanEqualTo(3) <= ImplementsGreaterThanEqualTo(3) with self.subTest("GT > GE"), self.assertRaises(TypeError): ImplementsGreaterThan(4) > ImplementsGreaterThanEqualTo(4) with self.subTest("GT > LT"), self.assertRaises(TypeError): ImplementsGreaterThan(5) > ImplementsLessThan(5) with self.subTest("GE >= GT"), self.assertRaises(TypeError): ImplementsGreaterThanEqualTo(6) >= ImplementsGreaterThan(6) with self.subTest("GE >= LE"), self.assertRaises(TypeError): ImplementsGreaterThanEqualTo(7) >= ImplementsLessThanEqualTo(7) with self.subTest("GE when equal"): a = ComparatorNotImplemented(8) b = ComparatorNotImplemented(8) self.assertEqual(a, b) with self.assertRaises(TypeError): a >= b with self.subTest("LE when equal"): a = ComparatorNotImplemented(9) b = ComparatorNotImplemented(9) self.assertEqual(a, b) with self.assertRaises(TypeError): a <= b def test_pickle(self): for proto in range(4, pickle.HIGHEST_PROTOCOL + 1): for name in '__lt__', '__gt__', '__le__', '__ge__': with self.subTest(method=name, proto=proto): method = getattr(Orderable_LT, name) method_copy = pickle.loads(pickle.dumps(method, proto)) self.assertIs(method_copy, method) @functools.total_ordering class Orderable_LT: def __init__(self, value): self.value = value def __lt__(self, other): return self.value < other.value def __eq__(self, other): return self.value == other.value class TestLRU: def test_lru(self): def orig(x, y): return 3 * x + y f = self.module.lru_cache(maxsize=20)(orig) hits, misses, maxsize, currsize = f.cache_info() self.assertEqual(maxsize, 20) self.assertEqual(currsize, 0) self.assertEqual(hits, 0) self.assertEqual(misses, 0) domain = range(5) for i in range(1000): x, y = choice(domain), choice(domain) actual = f(x, y) expected = orig(x, y) self.assertEqual(actual, expected) hits, misses, maxsize, currsize = f.cache_info() self.assertTrue(hits > misses) self.assertEqual(hits + misses, 1000) self.assertEqual(currsize, 20) f.cache_clear() # test clearing hits, misses, maxsize, currsize = f.cache_info() self.assertEqual(hits, 0) self.assertEqual(misses, 0) self.assertEqual(currsize, 0) f(x, y) hits, misses, maxsize, currsize = f.cache_info() self.assertEqual(hits, 0) self.assertEqual(misses, 1) self.assertEqual(currsize, 1) # Test bypassing the cache self.assertIs(f.__wrapped__, orig) f.__wrapped__(x, y) hits, misses, maxsize, currsize = f.cache_info() self.assertEqual(hits, 0) self.assertEqual(misses, 1) self.assertEqual(currsize, 1) # test size zero (which means "never-cache") @self.module.lru_cache(0) def f(): nonlocal f_cnt f_cnt += 1 return 20 self.assertEqual(f.cache_info().maxsize, 0) f_cnt = 0 for i in range(5): self.assertEqual(f(), 20) self.assertEqual(f_cnt, 5) hits, misses, maxsize, currsize = f.cache_info() self.assertEqual(hits, 0) self.assertEqual(misses, 5) self.assertEqual(currsize, 0) # test size one @self.module.lru_cache(1) def f(): nonlocal f_cnt f_cnt += 1 return 20 self.assertEqual(f.cache_info().maxsize, 1) f_cnt = 0 for i in range(5): self.assertEqual(f(), 20) self.assertEqual(f_cnt, 1) hits, misses, maxsize, currsize = f.cache_info() self.assertEqual(hits, 4) self.assertEqual(misses, 1) self.assertEqual(currsize, 1) # test size two @self.module.lru_cache(2) def f(x): nonlocal f_cnt f_cnt += 1 return x*10 self.assertEqual(f.cache_info().maxsize, 2) f_cnt = 0 for x in 7, 9, 7, 9, 7, 9, 8, 8, 8, 9, 9, 9, 8, 8, 8, 7: # * * * * self.assertEqual(f(x), x*10) self.assertEqual(f_cnt, 4) hits, misses, maxsize, currsize = f.cache_info() self.assertEqual(hits, 12) self.assertEqual(misses, 4) self.assertEqual(currsize, 2) def test_lru_with_maxsize_none(self): @self.module.lru_cache(maxsize=None) def fib(n): if n < 2: return n return fib(n-1) + fib(n-2) self.assertEqual([fib(n) for n in range(16)], [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610]) self.assertEqual(fib.cache_info(), self.module._CacheInfo(hits=28, misses=16, maxsize=None, currsize=16)) fib.cache_clear() self.assertEqual(fib.cache_info(), self.module._CacheInfo(hits=0, misses=0, maxsize=None, currsize=0)) def test_lru_with_maxsize_negative(self): @self.module.lru_cache(maxsize=-10) def eq(n): return n for i in (0, 1): self.assertEqual([eq(n) for n in range(150)], list(range(150))) self.assertEqual(eq.cache_info(), self.module._CacheInfo(hits=0, misses=300, maxsize=-10, currsize=1)) def test_lru_with_exceptions(self): # Verify that user_function exceptions get passed through without # creating a hard-to-read chained exception. # http://bugs.python.org/issue13177 for maxsize in (None, 128): @self.module.lru_cache(maxsize) def func(i): return 'abc'[i] self.assertEqual(func(0), 'a') with self.assertRaises(IndexError) as cm: func(15) self.assertIsNone(cm.exception.__context__) # Verify that the previous exception did not result in a cached entry with self.assertRaises(IndexError): func(15) def test_lru_with_types(self): for maxsize in (None, 128): @self.module.lru_cache(maxsize=maxsize, typed=True) def square(x): return x * x self.assertEqual(square(3), 9) self.assertEqual(type(square(3)), type(9)) self.assertEqual(square(3.0), 9.0) self.assertEqual(type(square(3.0)), type(9.0)) self.assertEqual(square(x=3), 9) self.assertEqual(type(square(x=3)), type(9)) self.assertEqual(square(x=3.0), 9.0) self.assertEqual(type(square(x=3.0)), type(9.0)) self.assertEqual(square.cache_info().hits, 4) self.assertEqual(square.cache_info().misses, 4) def test_lru_with_keyword_args(self): @self.module.lru_cache() def fib(n): if n < 2: return n return fib(n=n-1) + fib(n=n-2) self.assertEqual( [fib(n=number) for number in range(16)], [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610] ) self.assertEqual(fib.cache_info(), self.module._CacheInfo(hits=28, misses=16, maxsize=128, currsize=16)) fib.cache_clear() self.assertEqual(fib.cache_info(), self.module._CacheInfo(hits=0, misses=0, maxsize=128, currsize=0)) def test_lru_with_keyword_args_maxsize_none(self): @self.module.lru_cache(maxsize=None) def fib(n): if n < 2: return n return fib(n=n-1) + fib(n=n-2) self.assertEqual([fib(n=number) for number in range(16)], [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610]) self.assertEqual(fib.cache_info(), self.module._CacheInfo(hits=28, misses=16, maxsize=None, currsize=16)) fib.cache_clear() self.assertEqual(fib.cache_info(), self.module._CacheInfo(hits=0, misses=0, maxsize=None, currsize=0)) def test_lru_cache_decoration(self): def f(zomg: 'zomg_annotation'): """f doc string""" return 42 g = self.module.lru_cache()(f) for attr in self.module.WRAPPER_ASSIGNMENTS: self.assertEqual(getattr(g, attr), getattr(f, attr)) @unittest.skipUnless(threading, 'This test requires threading.') def test_lru_cache_threaded(self): n, m = 5, 11 def orig(x, y): return 3 * x + y f = self.module.lru_cache(maxsize=n*m)(orig) hits, misses, maxsize, currsize = f.cache_info() self.assertEqual(currsize, 0) start = threading.Event() def full(k): start.wait(10) for _ in range(m): self.assertEqual(f(k, 0), orig(k, 0)) def clear(): start.wait(10) for _ in range(2*m): f.cache_clear() orig_si = sys.getswitchinterval() sys.setswitchinterval(1e-6) try: # create n threads in order to fill cache threads = [threading.Thread(target=full, args=[k]) for k in range(n)] with support.start_threads(threads): start.set() hits, misses, maxsize, currsize = f.cache_info() if self.module is py_functools: # XXX: Why can be not equal? self.assertLessEqual(misses, n) self.assertLessEqual(hits, m*n - misses) else: self.assertEqual(misses, n) self.assertEqual(hits, m*n - misses) self.assertEqual(currsize, n) # create n threads in order to fill cache and 1 to clear it threads = [threading.Thread(target=clear)] threads += [threading.Thread(target=full, args=[k]) for k in range(n)] start.clear() with support.start_threads(threads): start.set() finally: sys.setswitchinterval(orig_si) @unittest.skipUnless(threading, 'This test requires threading.') def test_lru_cache_threaded2(self): # Simultaneous call with the same arguments n, m = 5, 7 start = threading.Barrier(n+1) pause = threading.Barrier(n+1) stop = threading.Barrier(n+1) @self.module.lru_cache(maxsize=m*n) def f(x): pause.wait(10) return 3 * x self.assertEqual(f.cache_info(), (0, 0, m*n, 0)) def test(): for i in range(m): start.wait(10) self.assertEqual(f(i), 3 * i) stop.wait(10) threads = [threading.Thread(target=test) for k in range(n)] with support.start_threads(threads): for i in range(m): start.wait(10) stop.reset() pause.wait(10) start.reset() stop.wait(10) pause.reset() self.assertEqual(f.cache_info(), (0, (i+1)*n, m*n, i+1)) def test_need_for_rlock(self): # This will deadlock on an LRU cache that uses a regular lock @self.module.lru_cache(maxsize=10) def test_func(x): 'Used to demonstrate a reentrant lru_cache call within a single thread' return x class DoubleEq: 'Demonstrate a reentrant lru_cache call within a single thread' def __init__(self, x): self.x = x def __hash__(self): return self.x def __eq__(self, other): if self.x == 2: test_func(DoubleEq(1)) return self.x == other.x test_func(DoubleEq(1)) # Load the cache test_func(DoubleEq(2)) # Load the cache self.assertEqual(test_func(DoubleEq(2)), # Trigger a re-entrant __eq__ call DoubleEq(2)) # Verify the correct return value def test_early_detection_of_bad_call(self): # Issue #22184 with self.assertRaises(TypeError): @functools.lru_cache def f(): pass def test_lru_method(self): class X(int): f_cnt = 0 @self.module.lru_cache(2) def f(self, x): self.f_cnt += 1 return x*10+self a = X(5) b = X(5) c = X(7) self.assertEqual(X.f.cache_info(), (0, 0, 2, 0)) for x in 1, 2, 2, 3, 1, 1, 1, 2, 3, 3: self.assertEqual(a.f(x), x*10 + 5) self.assertEqual((a.f_cnt, b.f_cnt, c.f_cnt), (6, 0, 0)) self.assertEqual(X.f.cache_info(), (4, 6, 2, 2)) for x in 1, 2, 1, 1, 1, 1, 3, 2, 2, 2: self.assertEqual(b.f(x), x*10 + 5) self.assertEqual((a.f_cnt, b.f_cnt, c.f_cnt), (6, 4, 0)) self.assertEqual(X.f.cache_info(), (10, 10, 2, 2)) for x in 2, 1, 1, 1, 1, 2, 1, 3, 2, 1: self.assertEqual(c.f(x), x*10 + 7) self.assertEqual((a.f_cnt, b.f_cnt, c.f_cnt), (6, 4, 5)) self.assertEqual(X.f.cache_info(), (15, 15, 2, 2)) self.assertEqual(a.f.cache_info(), X.f.cache_info()) self.assertEqual(b.f.cache_info(), X.f.cache_info()) self.assertEqual(c.f.cache_info(), X.f.cache_info()) class TestLRUC(TestLRU, unittest.TestCase): module = c_functools class TestLRUPy(TestLRU, unittest.TestCase): module = py_functools class TestSingleDispatch(unittest.TestCase): def test_simple_overloads(self): @functools.singledispatch def g(obj): return "base" def g_int(i): return "integer" g.register(int, g_int) self.assertEqual(g("str"), "base") self.assertEqual(g(1), "integer") self.assertEqual(g([1,2,3]), "base") def test_mro(self): @functools.singledispatch def g(obj): return "base" class A: pass class C(A): pass class B(A): pass class D(C, B): pass def g_A(a): return "A" def g_B(b): return "B" g.register(A, g_A) g.register(B, g_B) self.assertEqual(g(A()), "A") self.assertEqual(g(B()), "B") self.assertEqual(g(C()), "A") self.assertEqual(g(D()), "B") def test_register_decorator(self): @functools.singledispatch def g(obj): return "base" @g.register(int) def g_int(i): return "int %s" % (i,) self.assertEqual(g(""), "base") self.assertEqual(g(12), "int 12") self.assertIs(g.dispatch(int), g_int) self.assertIs(g.dispatch(object), g.dispatch(str)) # Note: in the assert above this is not g. # @singledispatch returns the wrapper. def test_wrapping_attributes(self): @functools.singledispatch def g(obj): "Simple test" return "Test" self.assertEqual(g.__name__, "g") if sys.flags.optimize < 2: self.assertEqual(g.__doc__, "Simple test") @unittest.skipUnless(decimal, 'requires _decimal') @support.cpython_only def test_c_classes(self): @functools.singledispatch def g(obj): return "base" @g.register(decimal.DecimalException) def _(obj): return obj.args subn = decimal.Subnormal("Exponent < Emin") rnd = decimal.Rounded("Number got rounded") self.assertEqual(g(subn), ("Exponent < Emin",)) self.assertEqual(g(rnd), ("Number got rounded",)) @g.register(decimal.Subnormal) def _(obj): return "Too small to care." self.assertEqual(g(subn), "Too small to care.") self.assertEqual(g(rnd), ("Number got rounded",)) def test_compose_mro(self): # None of the examples in this test depend on haystack ordering. c = collections mro = functools._compose_mro bases = [c.Sequence, c.MutableMapping, c.Mapping, c.Set] for haystack in permutations(bases): m = mro(dict, haystack) self.assertEqual(m, [dict, c.MutableMapping, c.Mapping, c.Sized, c.Iterable, c.Container, object]) bases = [c.Container, c.Mapping, c.MutableMapping, c.OrderedDict] for haystack in permutations(bases): m = mro(c.ChainMap, haystack) self.assertEqual(m, [c.ChainMap, c.MutableMapping, c.Mapping, c.Sized, c.Iterable, c.Container, object]) # If there's a generic function with implementations registered for # both Sized and Container, passing a defaultdict to it results in an # ambiguous dispatch which will cause a RuntimeError (see # test_mro_conflicts). bases = [c.Container, c.Sized, str] for haystack in permutations(bases): m = mro(c.defaultdict, [c.Sized, c.Container, str]) self.assertEqual(m, [c.defaultdict, dict, c.Sized, c.Container, object]) # MutableSequence below is registered directly on D. In other words, it # preceeds MutableMapping which means single dispatch will always # choose MutableSequence here. class D(c.defaultdict): pass c.MutableSequence.register(D) bases = [c.MutableSequence, c.MutableMapping] for haystack in permutations(bases): m = mro(D, bases) self.assertEqual(m, [D, c.MutableSequence, c.Sequence, c.defaultdict, dict, c.MutableMapping, c.Mapping, c.Sized, c.Iterable, c.Container, object]) # Container and Callable are registered on different base classes and # a generic function supporting both should always pick the Callable # implementation if a C instance is passed. class C(c.defaultdict): def __call__(self): pass bases = [c.Sized, c.Callable, c.Container, c.Mapping] for haystack in permutations(bases): m = mro(C, haystack) self.assertEqual(m, [C, c.Callable, c.defaultdict, dict, c.Mapping, c.Sized, c.Iterable, c.Container, object]) def test_register_abc(self): c = collections d = {"a": "b"} l = [1, 2, 3] s = {object(), None} f = frozenset(s) t = (1, 2, 3) @functools.singledispatch def g(obj): return "base" self.assertEqual(g(d), "base") self.assertEqual(g(l), "base") self.assertEqual(g(s), "base") self.assertEqual(g(f), "base") self.assertEqual(g(t), "base") g.register(c.Sized, lambda obj: "sized") self.assertEqual(g(d), "sized") self.assertEqual(g(l), "sized") self.assertEqual(g(s), "sized") self.assertEqual(g(f), "sized") self.assertEqual(g(t), "sized") g.register(c.MutableMapping, lambda obj: "mutablemapping") self.assertEqual(g(d), "mutablemapping") self.assertEqual(g(l), "sized") self.assertEqual(g(s), "sized") self.assertEqual(g(f), "sized") self.assertEqual(g(t), "sized") g.register(c.ChainMap, lambda obj: "chainmap") self.assertEqual(g(d), "mutablemapping") # irrelevant ABCs registered self.assertEqual(g(l), "sized") self.assertEqual(g(s), "sized") self.assertEqual(g(f), "sized") self.assertEqual(g(t), "sized") g.register(c.MutableSequence, lambda obj: "mutablesequence") self.assertEqual(g(d), "mutablemapping") self.assertEqual(g(l), "mutablesequence") self.assertEqual(g(s), "sized") self.assertEqual(g(f), "sized") self.assertEqual(g(t), "sized") g.register(c.MutableSet, lambda obj: "mutableset") self.assertEqual(g(d), "mutablemapping") self.assertEqual(g(l), "mutablesequence") self.assertEqual(g(s), "mutableset") self.assertEqual(g(f), "sized") self.assertEqual(g(t), "sized") g.register(c.Mapping, lambda obj: "mapping") self.assertEqual(g(d), "mutablemapping") # not specific enough self.assertEqual(g(l), "mutablesequence") self.assertEqual(g(s), "mutableset") self.assertEqual(g(f), "sized") self.assertEqual(g(t), "sized") g.register(c.Sequence, lambda obj: "sequence") self.assertEqual(g(d), "mutablemapping") self.assertEqual(g(l), "mutablesequence") self.assertEqual(g(s), "mutableset") self.assertEqual(g(f), "sized") self.assertEqual(g(t), "sequence") g.register(c.Set, lambda obj: "set") self.assertEqual(g(d), "mutablemapping") self.assertEqual(g(l), "mutablesequence") self.assertEqual(g(s), "mutableset") self.assertEqual(g(f), "set") self.assertEqual(g(t), "sequence") g.register(dict, lambda obj: "dict") self.assertEqual(g(d), "dict") self.assertEqual(g(l), "mutablesequence") self.assertEqual(g(s), "mutableset") self.assertEqual(g(f), "set") self.assertEqual(g(t), "sequence") g.register(list, lambda obj: "list") self.assertEqual(g(d), "dict") self.assertEqual(g(l), "list") self.assertEqual(g(s), "mutableset") self.assertEqual(g(f), "set") self.assertEqual(g(t), "sequence") g.register(set, lambda obj: "concrete-set") self.assertEqual(g(d), "dict") self.assertEqual(g(l), "list") self.assertEqual(g(s), "concrete-set") self.assertEqual(g(f), "set") self.assertEqual(g(t), "sequence") g.register(frozenset, lambda obj: "frozen-set") self.assertEqual(g(d), "dict") self.assertEqual(g(l), "list") self.assertEqual(g(s), "concrete-set") self.assertEqual(g(f), "frozen-set") self.assertEqual(g(t), "sequence") g.register(tuple, lambda obj: "tuple") self.assertEqual(g(d), "dict") self.assertEqual(g(l), "list") self.assertEqual(g(s), "concrete-set") self.assertEqual(g(f), "frozen-set") self.assertEqual(g(t), "tuple") def test_c3_abc(self): c = collections mro = functools._c3_mro class A(object): pass class B(A): def __len__(self): return 0 # implies Sized @c.Container.register class C(object): pass class D(object): pass # unrelated class X(D, C, B): def __call__(self): pass # implies Callable expected = [X, c.Callable, D, C, c.Container, B, c.Sized, A, object] for abcs in permutations([c.Sized, c.Callable, c.Container]): self.assertEqual(mro(X, abcs=abcs), expected) # unrelated ABCs don't appear in the resulting MRO many_abcs = [c.Mapping, c.Sized, c.Callable, c.Container, c.Iterable] self.assertEqual(mro(X, abcs=many_abcs), expected) def test_false_meta(self): # see issue23572 class MetaA(type): def __len__(self): return 0 class A(metaclass=MetaA): pass class AA(A): pass @functools.singledispatch def fun(a): return 'base A' @fun.register(A) def _(a): return 'fun A' aa = AA() self.assertEqual(fun(aa), 'fun A') def test_mro_conflicts(self): c = collections @functools.singledispatch def g(arg): return "base" class O(c.Sized): def __len__(self): return 0 o = O() self.assertEqual(g(o), "base") g.register(c.Iterable, lambda arg: "iterable") g.register(c.Container, lambda arg: "container") g.register(c.Sized, lambda arg: "sized") g.register(c.Set, lambda arg: "set") self.assertEqual(g(o), "sized") c.Iterable.register(O) self.assertEqual(g(o), "sized") # because it's explicitly in __mro__ c.Container.register(O) self.assertEqual(g(o), "sized") # see above: Sized is in __mro__ c.Set.register(O) self.assertEqual(g(o), "set") # because c.Set is a subclass of # c.Sized and c.Container class P: pass p = P() self.assertEqual(g(p), "base") c.Iterable.register(P) self.assertEqual(g(p), "iterable") c.Container.register(P) with self.assertRaises(RuntimeError) as re_one: g(p) self.assertIn( str(re_one.exception), (("Ambiguous dispatch: " "or "), ("Ambiguous dispatch: " "or ")), ) class Q(c.Sized): def __len__(self): return 0 q = Q() self.assertEqual(g(q), "sized") c.Iterable.register(Q) self.assertEqual(g(q), "sized") # because it's explicitly in __mro__ c.Set.register(Q) self.assertEqual(g(q), "set") # because c.Set is a subclass of # c.Sized and c.Iterable @functools.singledispatch def h(arg): return "base" @h.register(c.Sized) def _(arg): return "sized" @h.register(c.Container) def _(arg): return "container" # Even though Sized and Container are explicit bases of MutableMapping, # this ABC is implicitly registered on defaultdict which makes all of # MutableMapping's bases implicit as well from defaultdict's # perspective. with self.assertRaises(RuntimeError) as re_two: h(c.defaultdict(lambda: 0)) self.assertIn( str(re_two.exception), (("Ambiguous dispatch: " "or "), ("Ambiguous dispatch: " "or ")), ) class R(c.defaultdict): pass c.MutableSequence.register(R) @functools.singledispatch def i(arg): return "base" @i.register(c.MutableMapping) def _(arg): return "mapping" @i.register(c.MutableSequence) def _(arg): return "sequence" r = R() self.assertEqual(i(r), "sequence") class S: pass class T(S, c.Sized): def __len__(self): return 0 t = T() self.assertEqual(h(t), "sized") c.Container.register(T) self.assertEqual(h(t), "sized") # because it's explicitly in the MRO class U: def __len__(self): return 0 u = U() self.assertEqual(h(u), "sized") # implicit Sized subclass inferred # from the existence of __len__() c.Container.register(U) # There is no preference for registered versus inferred ABCs. with self.assertRaises(RuntimeError) as re_three: h(u) self.assertIn( str(re_three.exception), (("Ambiguous dispatch: " "or "), ("Ambiguous dispatch: " "or ")), ) class V(c.Sized, S): def __len__(self): return 0 @functools.singledispatch def j(arg): return "base" @j.register(S) def _(arg): return "s" @j.register(c.Container) def _(arg): return "container" v = V() self.assertEqual(j(v), "s") c.Container.register(V) self.assertEqual(j(v), "container") # because it ends up right after # Sized in the MRO def test_cache_invalidation(self): from collections import UserDict class TracingDict(UserDict): def __init__(self, *args, **kwargs): super(TracingDict, self).__init__(*args, **kwargs) self.set_ops = [] self.get_ops = [] def __getitem__(self, key): result = self.data[key] self.get_ops.append(key) return result def __setitem__(self, key, value): self.set_ops.append(key) self.data[key] = value def clear(self): self.data.clear() _orig_wkd = functools.WeakKeyDictionary td = TracingDict() functools.WeakKeyDictionary = lambda: td c = collections @functools.singledispatch def g(arg): return "base" d = {} l = [] self.assertEqual(len(td), 0) self.assertEqual(g(d), "base") self.assertEqual(len(td), 1) self.assertEqual(td.get_ops, []) self.assertEqual(td.set_ops, [dict]) self.assertEqual(td.data[dict], g.registry[object]) self.assertEqual(g(l), "base") self.assertEqual(len(td), 2) self.assertEqual(td.get_ops, []) self.assertEqual(td.set_ops, [dict, list]) self.assertEqual(td.data[dict], g.registry[object]) self.assertEqual(td.data[list], g.registry[object]) self.assertEqual(td.data[dict], td.data[list]) self.assertEqual(g(l), "base") self.assertEqual(g(d), "base") self.assertEqual(td.get_ops, [list, dict]) self.assertEqual(td.set_ops, [dict, list]) g.register(list, lambda arg: "list") self.assertEqual(td.get_ops, [list, dict]) self.assertEqual(len(td), 0) self.assertEqual(g(d), "base") self.assertEqual(len(td), 1) self.assertEqual(td.get_ops, [list, dict]) self.assertEqual(td.set_ops, [dict, list, dict]) self.assertEqual(td.data[dict], functools._find_impl(dict, g.registry)) self.assertEqual(g(l), "list") self.assertEqual(len(td), 2) self.assertEqual(td.get_ops, [list, dict]) self.assertEqual(td.set_ops, [dict, list, dict, list]) self.assertEqual(td.data[list], functools._find_impl(list, g.registry)) class X: pass c.MutableMapping.register(X) # Will not invalidate the cache, # not using ABCs yet. self.assertEqual(g(d), "base") self.assertEqual(g(l), "list") self.assertEqual(td.get_ops, [list, dict, dict, list]) self.assertEqual(td.set_ops, [dict, list, dict, list]) g.register(c.Sized, lambda arg: "sized") self.assertEqual(len(td), 0) self.assertEqual(g(d), "sized") self.assertEqual(len(td), 1) self.assertEqual(td.get_ops, [list, dict, dict, list]) self.assertEqual(td.set_ops, [dict, list, dict, list, dict]) self.assertEqual(g(l), "list") self.assertEqual(len(td), 2) self.assertEqual(td.get_ops, [list, dict, dict, list]) self.assertEqual(td.set_ops, [dict, list, dict, list, dict, list]) self.assertEqual(g(l), "list") self.assertEqual(g(d), "sized") self.assertEqual(td.get_ops, [list, dict, dict, list, list, dict]) self.assertEqual(td.set_ops, [dict, list, dict, list, dict, list]) g.dispatch(list) g.dispatch(dict) self.assertEqual(td.get_ops, [list, dict, dict, list, list, dict, list, dict]) self.assertEqual(td.set_ops, [dict, list, dict, list, dict, list]) c.MutableSet.register(X) # Will invalidate the cache. self.assertEqual(len(td), 2) # Stale cache. self.assertEqual(g(l), "list") self.assertEqual(len(td), 1) g.register(c.MutableMapping, lambda arg: "mutablemapping") self.assertEqual(len(td), 0) self.assertEqual(g(d), "mutablemapping") self.assertEqual(len(td), 1) self.assertEqual(g(l), "list") self.assertEqual(len(td), 2) g.register(dict, lambda arg: "dict") self.assertEqual(g(d), "dict") self.assertEqual(g(l), "list") g._clear_cache() self.assertEqual(len(td), 0) functools.WeakKeyDictionary = _orig_wkd if __name__ == '__main__': unittest.main()