Raymond Hettinger | 9c323f8 | 2005-02-28 19:39:44 +0000 | [diff] [blame^] | 1 | import functional |
| 2 | import unittest |
| 3 | from test import test_support |
| 4 | |
| 5 | @staticmethod |
| 6 | def PythonPartial(func, *args, **keywords): |
| 7 | 'Pure Python approximation of partial()' |
| 8 | def newfunc(*fargs, **fkeywords): |
| 9 | newkeywords = keywords.copy() |
| 10 | newkeywords.update(fkeywords) |
| 11 | return func(*(args + fargs), **newkeywords) |
| 12 | newfunc.func = func |
| 13 | newfunc.args = args |
| 14 | newfunc.keywords = keywords |
| 15 | return newfunc |
| 16 | |
| 17 | def capture(*args, **kw): |
| 18 | """capture all positional and keyword arguments""" |
| 19 | return args, kw |
| 20 | |
| 21 | class TestPartial(unittest.TestCase): |
| 22 | |
| 23 | thetype = functional.partial |
| 24 | |
| 25 | def test_basic_examples(self): |
| 26 | p = self.thetype(capture, 1, 2, a=10, b=20) |
| 27 | self.assertEqual(p(3, 4, b=30, c=40), |
| 28 | ((1, 2, 3, 4), dict(a=10, b=30, c=40))) |
| 29 | p = self.thetype(map, lambda x: x*10) |
| 30 | self.assertEqual(p([1,2,3,4]), [10, 20, 30, 40]) |
| 31 | |
| 32 | def test_attributes(self): |
| 33 | p = self.thetype(capture, 1, 2, a=10, b=20) |
| 34 | # attributes should be readable |
| 35 | self.assertEqual(p.func, capture) |
| 36 | self.assertEqual(p.args, (1, 2)) |
| 37 | self.assertEqual(p.keywords, dict(a=10, b=20)) |
| 38 | # attributes should not be writable |
| 39 | if not isinstance(self.thetype, type): |
| 40 | return |
| 41 | self.assertRaises(TypeError, setattr, p, 'func', map) |
| 42 | self.assertRaises(TypeError, setattr, p, 'args', (1, 2)) |
| 43 | self.assertRaises(TypeError, setattr, p, 'keywords', dict(a=1, b=2)) |
| 44 | |
| 45 | def test_argument_checking(self): |
| 46 | self.assertRaises(TypeError, self.thetype) # need at least a func arg |
| 47 | try: |
| 48 | self.thetype(2)() |
| 49 | except TypeError: |
| 50 | pass |
| 51 | else: |
| 52 | self.fail('First arg not checked for callability') |
| 53 | |
| 54 | def test_protection_of_callers_dict_argument(self): |
| 55 | # a caller's dictionary should not be altered by partial |
| 56 | def func(a=10, b=20): |
| 57 | return a |
| 58 | d = {'a':3} |
| 59 | p = self.thetype(func, a=5) |
| 60 | self.assertEqual(p(**d), 3) |
| 61 | self.assertEqual(d, {'a':3}) |
| 62 | p(b=7) |
| 63 | self.assertEqual(d, {'a':3}) |
| 64 | |
| 65 | def test_arg_combinations(self): |
| 66 | # exercise special code paths for zero args in either partial |
| 67 | # object or the caller |
| 68 | p = self.thetype(capture) |
| 69 | self.assertEqual(p(), ((), {})) |
| 70 | self.assertEqual(p(1,2), ((1,2), {})) |
| 71 | p = self.thetype(capture, 1, 2) |
| 72 | self.assertEqual(p(), ((1,2), {})) |
| 73 | self.assertEqual(p(3,4), ((1,2,3,4), {})) |
| 74 | |
| 75 | def test_kw_combinations(self): |
| 76 | # exercise special code paths for no keyword args in |
| 77 | # either the partial object or the caller |
| 78 | p = self.thetype(capture) |
| 79 | self.assertEqual(p(), ((), {})) |
| 80 | self.assertEqual(p(a=1), ((), {'a':1})) |
| 81 | p = self.thetype(capture, a=1) |
| 82 | self.assertEqual(p(), ((), {'a':1})) |
| 83 | self.assertEqual(p(b=2), ((), {'a':1, 'b':2})) |
| 84 | # keyword args in the call override those in the partial object |
| 85 | self.assertEqual(p(a=3, b=2), ((), {'a':3, 'b':2})) |
| 86 | |
| 87 | def test_positional(self): |
| 88 | # make sure positional arguments are captured correctly |
| 89 | for args in [(), (0,), (0,1), (0,1,2), (0,1,2,3)]: |
| 90 | p = self.thetype(capture, *args) |
| 91 | expected = args + ('x',) |
| 92 | got, empty = p('x') |
| 93 | self.failUnless(expected == got and empty == {}) |
| 94 | |
| 95 | def test_keyword(self): |
| 96 | # make sure keyword arguments are captured correctly |
| 97 | for a in ['a', 0, None, 3.5]: |
| 98 | p = self.thetype(capture, a=a) |
| 99 | expected = {'a':a,'x':None} |
| 100 | empty, got = p(x=None) |
| 101 | self.failUnless(expected == got and empty == ()) |
| 102 | |
| 103 | def test_no_side_effects(self): |
| 104 | # make sure there are no side effects that affect subsequent calls |
| 105 | p = self.thetype(capture, 0, a=1) |
| 106 | args1, kw1 = p(1, b=2) |
| 107 | self.failUnless(args1 == (0,1) and kw1 == {'a':1,'b':2}) |
| 108 | args2, kw2 = p() |
| 109 | self.failUnless(args2 == (0,) and kw2 == {'a':1}) |
| 110 | |
| 111 | def test_error_propagation(self): |
| 112 | def f(x, y): |
| 113 | x / y |
| 114 | self.assertRaises(ZeroDivisionError, self.thetype(f, 1, 0)) |
| 115 | self.assertRaises(ZeroDivisionError, self.thetype(f, 1), 0) |
| 116 | self.assertRaises(ZeroDivisionError, self.thetype(f), 1, 0) |
| 117 | self.assertRaises(ZeroDivisionError, self.thetype(f, y=0), 1) |
| 118 | |
| 119 | |
| 120 | class PartialSubclass(functional.partial): |
| 121 | pass |
| 122 | |
| 123 | class TestPartialSubclass(TestPartial): |
| 124 | |
| 125 | thetype = PartialSubclass |
| 126 | |
| 127 | |
| 128 | class TestPythonPartial(TestPartial): |
| 129 | |
| 130 | thetype = PythonPartial |
| 131 | |
| 132 | |
| 133 | |
| 134 | def test_main(verbose=None): |
| 135 | import sys |
| 136 | test_classes = ( |
| 137 | TestPartial, |
| 138 | TestPartialSubclass, |
| 139 | TestPythonPartial, |
| 140 | ) |
| 141 | test_support.run_unittest(*test_classes) |
| 142 | |
| 143 | # verify reference counting |
| 144 | if verbose and hasattr(sys, "gettotalrefcount"): |
| 145 | import gc |
| 146 | counts = [None] * 5 |
| 147 | for i in xrange(len(counts)): |
| 148 | test_support.run_unittest(*test_classes) |
| 149 | gc.collect() |
| 150 | counts[i] = sys.gettotalrefcount() |
| 151 | print counts |
| 152 | |
| 153 | if __name__ == '__main__': |
| 154 | test_main(verbose=True) |