gen_test.py 文件源码

def test_iterator_async_await(self):
        # Recreate the previous test with py35 syntax. It's a little clunky
        # because of the way the previous test handles an exception on
        # a single iteration.
        futures = [Future(), Future(), Future(), Future()]
        self.finish_coroutines(0, futures)
        self.finished = False

        namespace = exec_test(globals(), locals(), """
        async def f():
            i = 0
            g = gen.WaitIterator(*futures)
            try:
                async for r in g:
                    if i == 0:
                        self.assertEqual(r, 24, 'iterator value incorrect')
                        self.assertEqual(g.current_index, 2, 'wrong index')
                    else:
                        raise Exception("expected exception on iteration 1")
                    i += 1
            except ZeroDivisionError:
                i += 1
            async for r in g:
                if i == 2:
                    self.assertEqual(r, 42, 'iterator value incorrect')
                    self.assertEqual(g.current_index, 1, 'wrong index')
                elif i == 3:
                    self.assertEqual(r, 84, 'iterator value incorrect')
                    self.assertEqual(g.current_index, 3, 'wrong index')
                else:
                    raise Exception("didn't expect iteration %d" % i)
                i += 1
            self.finished = True
        """)
        yield namespace['f']()
        self.assertTrue(self.finished)