import functools import unittest from test import test_support from weakref import proxy @staticmethod def PythonPartial(func, *args, **keywords): 'Pure Python approximation of partial()' def newfunc(*fargs, **fkeywords): newkeywords = keywords.copy() newkeywords.update(fkeywords) return func(*(args + fargs), **newkeywords) newfunc.func = func newfunc.args = args newfunc.keywords = keywords return newfunc def capture(*args, **kw): """capture all positional and keyword arguments""" return args, kw class TestPartial(unittest.TestCase): thetype = functools.partial def test_basic_examples(self): p = self.thetype(capture, 1, 2, a=10, b=20) self.assertEqual(p(3, 4, b=30, c=40), ((1, 2, 3, 4), dict(a=10, b=30, c=40))) p = self.thetype(map, lambda x: x*10) self.assertEqual(list(p([1,2,3,4])), [10, 20, 30, 40]) def test_attributes(self): p = self.thetype(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)) # attributes should not be writable if not isinstance(self.thetype, type): return self.assertRaises(TypeError, setattr, p, 'func', map) self.assertRaises(TypeError, setattr, p, 'args', (1, 2)) self.assertRaises(TypeError, setattr, p, 'keywords', dict(a=1, b=2)) def test_argument_checking(self): self.assertRaises(TypeError, self.thetype) # need at least a func arg try: self.thetype(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.thetype(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.thetype(capture) self.assertEqual(p(), ((), {})) self.assertEqual(p(1,2), ((1,2), {})) p = self.thetype(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.thetype(capture) self.assertEqual(p(), ((), {})) self.assertEqual(p(a=1), ((), {'a':1})) p = self.thetype(capture, 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.thetype(capture, *args) expected = args + ('x',) got, empty = p('x') self.failUnless(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.thetype(capture, a=a) expected = {'a':a,'x':None} empty, got = p(x=None) self.failUnless(expected == got and empty == ()) def test_no_side_effects(self): # make sure there are no side effects that affect subsequent calls p = self.thetype(capture, 0, a=1) args1, kw1 = p(1, b=2) self.failUnless(args1 == (0,1) and kw1 == {'a':1,'b':2}) args2, kw2 = p() self.failUnless(args2 == (0,) and kw2 == {'a':1}) def test_error_propagation(self): def f(x, y): x / y self.assertRaises(ZeroDivisionError, self.thetype(f, 1, 0)) self.assertRaises(ZeroDivisionError, self.thetype(f, 1), 0) self.assertRaises(ZeroDivisionError, self.thetype(f), 1, 0) self.assertRaises(ZeroDivisionError, self.thetype(f, y=0), 1) def test_attributes(self): p = self.thetype(hex) try: del p.__dict__ except TypeError: pass else: self.fail('partial object allowed __dict__ to be deleted') def test_weakref(self): f = self.thetype(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.thetype(str.join, '') self.assertEqual(join(data), '0123456789') join = self.thetype(''.join) self.assertEqual(join(data), '0123456789') class PartialSubclass(functools.partial): pass class TestPartialSubclass(TestPartial): thetype = PartialSubclass class TestPythonPartial(TestPartial): thetype = PythonPartial 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.failUnless(getattr(wrapper, name) is 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: self.failUnless(wrapped_attr[key] is wrapper_attr[key]) def test_default_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__, 'f') self.assertEqual(wrapper.__doc__, 'This is a test') self.assertEqual(wrapper.attr, 'This is also 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.assertEqual(wrapper.__doc__, None) self.failIf(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.assertEqual(wrapper.__doc__, None) self.assertEqual(wrapper.attr, 'This is a different test') self.assertEqual(wrapper.dict_attr, f.dict_attr) def test_builtin_update(self): # Test for bug #1576241 def wrapper(): pass functools.update_wrapper(wrapper, max) self.assertEqual(wrapper.__name__, 'max') self.assert_(wrapper.__doc__.startswith('max(')) class TestWraps(TestUpdateWrapper): def test_default_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__, 'f') self.assertEqual(wrapper.__doc__, 'This is a test') self.assertEqual(wrapper.attr, 'This is also 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.assertEqual(wrapper.__doc__, None) self.failIf(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.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] self.assertEqual(self.func(lambda x, y: x+y, ['a', 'b', 'c'], ''), 'abc') self.assertEqual( self.func(lambda x, y: x+y, [['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(lambda x, y: x+y, Squares(10)), 285) self.assertEqual(self.func(lambda x, y: x+y, Squares(10), 0), 285) self.assertEqual(self.func(lambda x, y: x+y, 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)) 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())) def test_main(verbose=None): import sys test_classes = ( TestPartial, TestPartialSubclass, TestPythonPartial, TestUpdateWrapper, TestWraps, TestReduce ) test_support.run_unittest(*test_classes) # verify reference counting if verbose and hasattr(sys, "gettotalrefcount"): import gc counts = [None] * 5 for i in range(len(counts)): test_support.run_unittest(*test_classes) gc.collect() counts[i] = sys.gettotalrefcount() print(counts) if __name__ == '__main__': test_main(verbose=True)