From 8b48cf9016a1eee969717854df20b59c2656a801 Mon Sep 17 00:00:00 2001 From: Guido van Rossum Date: Sat, 21 Apr 2001 13:33:54 +0000 Subject: [PATCH] Add test suite for iterators. --- Lib/test/output/test_iter | 1 + Lib/test/test_iter.py | 246 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 247 insertions(+) create mode 100644 Lib/test/output/test_iter create mode 100644 Lib/test/test_iter.py diff --git a/Lib/test/output/test_iter b/Lib/test/output/test_iter new file mode 100644 index 00000000000..7c6692f37b8 --- /dev/null +++ b/Lib/test/output/test_iter @@ -0,0 +1 @@ +test_iter diff --git a/Lib/test/test_iter.py b/Lib/test/test_iter.py new file mode 100644 index 00000000000..d4b8736293e --- /dev/null +++ b/Lib/test/test_iter.py @@ -0,0 +1,246 @@ +# Test iterators. + +import unittest +from test_support import run_unittest, TESTFN, unlink + +# Test result of triple loop (too big to inline) +TRIPLETS = [(0, 0, 0), (0, 0, 1), (0, 0, 2), + (0, 1, 0), (0, 1, 1), (0, 1, 2), + (0, 2, 0), (0, 2, 1), (0, 2, 2), + + (1, 0, 0), (1, 0, 1), (1, 0, 2), + (1, 1, 0), (1, 1, 1), (1, 1, 2), + (1, 2, 0), (1, 2, 1), (1, 2, 2), + + (2, 0, 0), (2, 0, 1), (2, 0, 2), + (2, 1, 0), (2, 1, 1), (2, 1, 2), + (2, 2, 0), (2, 2, 1), (2, 2, 2)] + +# Helper classes + +class BasicIterClass: + def __init__(self, n): + self.n = n + self.i = 0 + def next(self): + res = self.i + if res >= self.n: + raise StopIteration + self.i = res + 1 + return res + +class IteratingSequenceClass: + def __init__(self, n): + self.n = n + def __iter__(self): + return BasicIterClass(self.n) + +class SequenceClass: + def __init__(self, n): + self.n = n + def __getitem__(self, i): + if 0 <= i < self.n: + return i + else: + raise IndexError + +# Main test suite + +class TestCase(unittest.TestCase): + + # Helper to check that an iterator returns a given sequence + def check_iterator(self, it, seq): + res = [] + while 1: + try: + val = it.next() + except StopIteration: + break + res.append(val) + self.assertEqual(res, seq) + + # Helper to check that a for loop generates a given sequence + def check_for_loop(self, expr, seq): + res = [] + for val in expr: + res.append(val) + self.assertEqual(res, seq) + + # Test basic use of iter() function + def test_iter_basic(self): + self.check_iterator(iter(range(10)), range(10)) + + # Test that iter(iter(x)) is the same as iter(x) + def test_iter_idempotency(self): + seq = range(10) + it = iter(seq) + it2 = iter(it) + self.assert_(it is it2) + + # Test that for loops over iterators work + def test_iter_for_loop(self): + self.check_for_loop(iter(range(10)), range(10)) + + # Test several independent iterators over the same list + def test_iter_independence(self): + seq = range(3) + res = [] + for i in iter(seq): + for j in iter(seq): + for k in iter(seq): + res.append((i, j, k)) + self.assertEqual(res, TRIPLETS) + + # Test triple list comprehension using iterators + def test_nested_comprehensions_iter(self): + seq = range(3) + res = [(i, j, k) + for i in iter(seq) for j in iter(seq) for k in iter(seq)] + self.assertEqual(res, TRIPLETS) + + # Test triple list comprehension without iterators + def test_nested_comprehensions_for(self): + seq = range(3) + res = [(i, j, k) for i in seq for j in seq for k in seq] + self.assertEqual(res, TRIPLETS) + + # Test a class with __iter__ in a for loop + def test_iter_class_for(self): + self.check_for_loop(IteratingSequenceClass(10), range(10)) + + # Test a class with __iter__ with explicit iter() + def test_iter_class_iter(self): + self.check_iterator(iter(IteratingSequenceClass(10)), range(10)) + + # Test for loop on a sequence class without __iter__ + def test_seq_class_for(self): + self.check_for_loop(SequenceClass(10), range(10)) + + # Test iter() on a sequence class without __iter__ + def test_seq_class_iter(self): + self.check_iterator(iter(SequenceClass(10)), range(10)) + + # Test two-argument iter() with callable instance + def test_iter_callable(self): + class C: + def __init__(self): + self.i = 0 + def __call__(self): + i = self.i + self.i = i + 1 + if i > 100: + raise IndexError # Emergency stop + return i + self.check_iterator(iter(C(), 10), range(10)) + + # Test two-argument iter() with function + def test_iter_function(self): + def spam(state=[0]): + i = state[0] + state[0] = i+1 + return i + self.check_iterator(iter(spam, 10), range(10)) + + # Test two-argument iter() with function that raises StopIteration + def test_iter_function_stop(self): + def spam(state=[0]): + i = state[0] + if i == 10: + raise StopIteration + state[0] = i+1 + return i + self.check_iterator(iter(spam, 20), range(10)) + + # Test exception propagation through function iterator + def test_exception_function(self): + def spam(state=[0]): + i = state[0] + state[0] = i+1 + if i == 10: + raise RuntimeError + return i + res = [] + try: + for x in iter(spam, 20): + res.append(x) + except RuntimeError: + self.assertEqual(res, range(10)) + else: + self.fail("should have raised RuntimeError") + + # Test exception propagation through sequence iterator + def test_exception_sequence(self): + class MySequenceClass(SequenceClass): + def __getitem__(self, i): + if i == 10: + raise RuntimeError + return SequenceClass.__getitem__(self, i) + res = [] + try: + for x in MySequenceClass(20): + res.append(x) + except RuntimeError: + self.assertEqual(res, range(10)) + else: + self.fail("should have raised RuntimeError") + + # Test for StopIteration from __getitem__ + def test_stop_sequence(self): + class MySequenceClass(SequenceClass): + def __getitem__(self, i): + if i == 10: + raise StopIteration + return SequenceClass.__getitem__(self, i) + self.check_for_loop(MySequenceClass(20), range(10)) + + # Test a big range + def test_iter_big_range(self): + self.check_for_loop(iter(range(10000)), range(10000)) + + # Test an empty list + def test_iter_empty(self): + self.check_for_loop(iter([]), []) + + # Test a tuple + def test_iter_tuple(self): + self.check_for_loop(iter((0,1,2,3,4,5,6,7,8,9)), range(10)) + + # Test an xrange + def test_iter_xrange(self): + self.check_for_loop(iter(xrange(10)), range(10)) + + # Test a string + def test_iter_string(self): + self.check_for_loop(iter("abcde"), ["a", "b", "c", "d", "e"]) + + # Test a Unicode string + def test_iter_unicode(self): + self.check_for_loop(iter(u"abcde"), [u"a", u"b", u"c", u"d", u"e"]) + + # Test a directory + def test_iter_dict(self): + dict = {} + for i in range(10): + dict[i] = None + self.check_for_loop(dict, dict.keys()) + + # Test a file + def test_iter_file(self): + f = open(TESTFN, "w") + try: + for i in range(5): + f.write("%d\n" % i) + finally: + f.close() + f = open(TESTFN, "r") + try: + self.check_for_loop(f, ["0\n", "1\n", "2\n", "3\n", "4\n"]) + self.check_for_loop(f, []) + finally: + f.close() + try: + unlink(TESTFN) + except OSError: + pass + +run_unittest(TestCase)