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(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 if test_support.is_jython: from test_weakref import extra_collect extra_collect() self.assertRaises(ReferenceError, getattr, p, 'func') def test_with_bound_and_unbound_methods(self): data = 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) == 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) 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) def test_main(verbose=None): import sys test_classes = ( TestPartial, TestPartialSubclass, TestPythonPartial, TestUpdateWrapper, TestWraps ) test_support.run_unittest(*test_classes) # verify reference counting if verbose and hasattr(sys, "gettotalrefcount"): import gc counts = [None] * 5 for i in xrange(len(counts)): test_support.run_unittest(*test_classes) gc.collect() counts[i] = sys.gettotalrefcount() print counts if __name__ == '__main__': test_main(verbose=True)