mirror of https://github.com/python/cpython
651 lines
20 KiB
Python
651 lines
20 KiB
Python
# Test iterators.
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import unittest
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from test_support import run_unittest, TESTFN, unlink
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# Test result of triple loop (too big to inline)
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TRIPLETS = [(0, 0, 0), (0, 0, 1), (0, 0, 2),
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(0, 1, 0), (0, 1, 1), (0, 1, 2),
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(0, 2, 0), (0, 2, 1), (0, 2, 2),
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(1, 0, 0), (1, 0, 1), (1, 0, 2),
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(1, 1, 0), (1, 1, 1), (1, 1, 2),
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(1, 2, 0), (1, 2, 1), (1, 2, 2),
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(2, 0, 0), (2, 0, 1), (2, 0, 2),
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(2, 1, 0), (2, 1, 1), (2, 1, 2),
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(2, 2, 0), (2, 2, 1), (2, 2, 2)]
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# Helper classes
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class BasicIterClass:
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def __init__(self, n):
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self.n = n
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self.i = 0
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def next(self):
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res = self.i
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if res >= self.n:
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raise StopIteration
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self.i = res + 1
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return res
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class IteratingSequenceClass:
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def __init__(self, n):
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self.n = n
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def __iter__(self):
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return BasicIterClass(self.n)
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class SequenceClass:
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def __init__(self, n):
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self.n = n
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def __getitem__(self, i):
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if 0 <= i < self.n:
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return i
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else:
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raise IndexError
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# Main test suite
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class TestCase(unittest.TestCase):
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# Helper to check that an iterator returns a given sequence
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def check_iterator(self, it, seq):
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res = []
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while 1:
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try:
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val = it.next()
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except StopIteration:
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break
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res.append(val)
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self.assertEqual(res, seq)
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# Helper to check that a for loop generates a given sequence
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def check_for_loop(self, expr, seq):
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res = []
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for val in expr:
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res.append(val)
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self.assertEqual(res, seq)
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# Test basic use of iter() function
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def test_iter_basic(self):
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self.check_iterator(iter(range(10)), range(10))
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# Test that iter(iter(x)) is the same as iter(x)
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def test_iter_idempotency(self):
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seq = range(10)
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it = iter(seq)
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it2 = iter(it)
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self.assert_(it is it2)
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# Test that for loops over iterators work
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def test_iter_for_loop(self):
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self.check_for_loop(iter(range(10)), range(10))
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# Test several independent iterators over the same list
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def test_iter_independence(self):
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seq = range(3)
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res = []
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for i in iter(seq):
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for j in iter(seq):
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for k in iter(seq):
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res.append((i, j, k))
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self.assertEqual(res, TRIPLETS)
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# Test triple list comprehension using iterators
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def test_nested_comprehensions_iter(self):
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seq = range(3)
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res = [(i, j, k)
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for i in iter(seq) for j in iter(seq) for k in iter(seq)]
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self.assertEqual(res, TRIPLETS)
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# Test triple list comprehension without iterators
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def test_nested_comprehensions_for(self):
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seq = range(3)
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res = [(i, j, k) for i in seq for j in seq for k in seq]
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self.assertEqual(res, TRIPLETS)
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# Test a class with __iter__ in a for loop
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def test_iter_class_for(self):
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self.check_for_loop(IteratingSequenceClass(10), range(10))
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# Test a class with __iter__ with explicit iter()
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def test_iter_class_iter(self):
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self.check_iterator(iter(IteratingSequenceClass(10)), range(10))
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# Test for loop on a sequence class without __iter__
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def test_seq_class_for(self):
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self.check_for_loop(SequenceClass(10), range(10))
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# Test iter() on a sequence class without __iter__
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def test_seq_class_iter(self):
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self.check_iterator(iter(SequenceClass(10)), range(10))
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# Test two-argument iter() with callable instance
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def test_iter_callable(self):
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class C:
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def __init__(self):
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self.i = 0
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def __call__(self):
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i = self.i
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self.i = i + 1
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if i > 100:
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raise IndexError # Emergency stop
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return i
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self.check_iterator(iter(C(), 10), range(10))
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# Test two-argument iter() with function
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def test_iter_function(self):
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def spam(state=[0]):
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i = state[0]
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state[0] = i+1
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return i
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self.check_iterator(iter(spam, 10), range(10))
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# Test two-argument iter() with function that raises StopIteration
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def test_iter_function_stop(self):
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def spam(state=[0]):
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i = state[0]
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if i == 10:
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raise StopIteration
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state[0] = i+1
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return i
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self.check_iterator(iter(spam, 20), range(10))
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# Test exception propagation through function iterator
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def test_exception_function(self):
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def spam(state=[0]):
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i = state[0]
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state[0] = i+1
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if i == 10:
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raise RuntimeError
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return i
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res = []
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try:
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for x in iter(spam, 20):
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res.append(x)
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except RuntimeError:
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self.assertEqual(res, range(10))
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else:
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self.fail("should have raised RuntimeError")
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# Test exception propagation through sequence iterator
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def test_exception_sequence(self):
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class MySequenceClass(SequenceClass):
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def __getitem__(self, i):
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if i == 10:
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raise RuntimeError
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return SequenceClass.__getitem__(self, i)
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res = []
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try:
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for x in MySequenceClass(20):
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res.append(x)
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except RuntimeError:
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self.assertEqual(res, range(10))
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else:
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self.fail("should have raised RuntimeError")
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# Test for StopIteration from __getitem__
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def test_stop_sequence(self):
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class MySequenceClass(SequenceClass):
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def __getitem__(self, i):
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if i == 10:
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raise StopIteration
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return SequenceClass.__getitem__(self, i)
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self.check_for_loop(MySequenceClass(20), range(10))
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# Test a big range
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def test_iter_big_range(self):
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self.check_for_loop(iter(range(10000)), range(10000))
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# Test an empty list
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def test_iter_empty(self):
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self.check_for_loop(iter([]), [])
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# Test a tuple
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def test_iter_tuple(self):
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self.check_for_loop(iter((0,1,2,3,4,5,6,7,8,9)), range(10))
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# Test an xrange
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def test_iter_xrange(self):
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self.check_for_loop(iter(xrange(10)), range(10))
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# Test a string
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def test_iter_string(self):
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self.check_for_loop(iter("abcde"), ["a", "b", "c", "d", "e"])
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# Test a Unicode string
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def test_iter_unicode(self):
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self.check_for_loop(iter(u"abcde"), [u"a", u"b", u"c", u"d", u"e"])
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# Test a directory
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def test_iter_dict(self):
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dict = {}
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for i in range(10):
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dict[i] = None
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self.check_for_loop(dict, dict.keys())
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# Test a file
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def test_iter_file(self):
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f = open(TESTFN, "w")
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try:
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for i in range(5):
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f.write("%d\n" % i)
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finally:
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f.close()
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f = open(TESTFN, "r")
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try:
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self.check_for_loop(f, ["0\n", "1\n", "2\n", "3\n", "4\n"])
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self.check_for_loop(f, [])
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finally:
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f.close()
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try:
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unlink(TESTFN)
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except OSError:
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pass
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# Test list()'s use of iterators.
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def test_builtin_list(self):
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self.assertEqual(list(SequenceClass(5)), range(5))
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self.assertEqual(list(SequenceClass(0)), [])
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self.assertEqual(list(()), [])
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self.assertEqual(list(range(10, -1, -1)), range(10, -1, -1))
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d = {"one": 1, "two": 2, "three": 3}
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self.assertEqual(list(d), d.keys())
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self.assertRaises(TypeError, list, list)
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self.assertRaises(TypeError, list, 42)
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f = open(TESTFN, "w")
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try:
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for i in range(5):
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f.write("%d\n" % i)
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finally:
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f.close()
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f = open(TESTFN, "r")
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try:
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self.assertEqual(list(f), ["0\n", "1\n", "2\n", "3\n", "4\n"])
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f.seek(0, 0)
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self.assertEqual(list(f.xreadlines()),
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["0\n", "1\n", "2\n", "3\n", "4\n"])
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finally:
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f.close()
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try:
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unlink(TESTFN)
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except OSError:
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pass
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# Test tuples()'s use of iterators.
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def test_builtin_tuple(self):
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self.assertEqual(tuple(SequenceClass(5)), (0, 1, 2, 3, 4))
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self.assertEqual(tuple(SequenceClass(0)), ())
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self.assertEqual(tuple([]), ())
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self.assertEqual(tuple(()), ())
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self.assertEqual(tuple("abc"), ("a", "b", "c"))
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d = {"one": 1, "two": 2, "three": 3}
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self.assertEqual(tuple(d), tuple(d.keys()))
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self.assertRaises(TypeError, tuple, list)
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self.assertRaises(TypeError, tuple, 42)
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f = open(TESTFN, "w")
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try:
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for i in range(5):
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f.write("%d\n" % i)
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finally:
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f.close()
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f = open(TESTFN, "r")
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try:
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self.assertEqual(tuple(f), ("0\n", "1\n", "2\n", "3\n", "4\n"))
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f.seek(0, 0)
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self.assertEqual(tuple(f.xreadlines()),
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("0\n", "1\n", "2\n", "3\n", "4\n"))
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finally:
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f.close()
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try:
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unlink(TESTFN)
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except OSError:
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pass
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# Test filter()'s use of iterators.
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def test_builtin_filter(self):
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self.assertEqual(filter(None, SequenceClass(5)), range(1, 5))
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self.assertEqual(filter(None, SequenceClass(0)), [])
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self.assertEqual(filter(None, ()), ())
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self.assertEqual(filter(None, "abc"), "abc")
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d = {"one": 1, "two": 2, "three": 3}
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self.assertEqual(filter(None, d), d.keys())
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self.assertRaises(TypeError, filter, None, list)
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self.assertRaises(TypeError, filter, None, 42)
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class Boolean:
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def __init__(self, truth):
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self.truth = truth
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def __nonzero__(self):
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return self.truth
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True = Boolean(1)
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False = Boolean(0)
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class Seq:
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def __init__(self, *args):
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self.vals = args
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def __iter__(self):
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class SeqIter:
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def __init__(self, vals):
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self.vals = vals
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self.i = 0
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def __iter__(self):
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return self
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def next(self):
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i = self.i
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self.i = i + 1
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if i < len(self.vals):
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return self.vals[i]
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else:
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raise StopIteration
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return SeqIter(self.vals)
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seq = Seq(*([True, False] * 25))
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self.assertEqual(filter(lambda x: not x, seq), [False]*25)
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self.assertEqual(filter(lambda x: not x, iter(seq)), [False]*25)
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# Test max() and min()'s use of iterators.
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def test_builtin_max_min(self):
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self.assertEqual(max(SequenceClass(5)), 4)
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self.assertEqual(min(SequenceClass(5)), 0)
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self.assertEqual(max(8, -1), 8)
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self.assertEqual(min(8, -1), -1)
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d = {"one": 1, "two": 2, "three": 3}
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self.assertEqual(max(d), "two")
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self.assertEqual(min(d), "one")
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self.assertEqual(max(d.itervalues()), 3)
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self.assertEqual(min(iter(d.itervalues())), 1)
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f = open(TESTFN, "w")
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try:
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f.write("medium line\n")
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f.write("xtra large line\n")
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f.write("itty-bitty line\n")
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finally:
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f.close()
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f = open(TESTFN, "r")
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try:
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self.assertEqual(min(f), "itty-bitty line\n")
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f.seek(0, 0)
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self.assertEqual(max(f), "xtra large line\n")
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finally:
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f.close()
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try:
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unlink(TESTFN)
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except OSError:
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pass
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# Test map()'s use of iterators.
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def test_builtin_map(self):
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self.assertEqual(map(None, SequenceClass(5)), range(5))
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self.assertEqual(map(lambda x: x+1, SequenceClass(5)), range(1, 6))
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d = {"one": 1, "two": 2, "three": 3}
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self.assertEqual(map(None, d), d.keys())
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self.assertEqual(map(lambda k, d=d: (k, d[k]), d), d.items())
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dkeys = d.keys()
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expected = [(i < len(d) and dkeys[i] or None,
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i,
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i < len(d) and dkeys[i] or None)
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for i in range(5)]
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self.assertEqual(map(None, d,
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SequenceClass(5),
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iter(d.iterkeys())),
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expected)
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f = open(TESTFN, "w")
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try:
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for i in range(10):
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f.write("xy" * i + "\n") # line i has len 2*i+1
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finally:
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f.close()
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f = open(TESTFN, "r")
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try:
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self.assertEqual(map(len, f), range(1, 21, 2))
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finally:
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f.close()
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try:
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unlink(TESTFN)
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except OSError:
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pass
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# Test zip()'s use of iterators.
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def test_builtin_zip(self):
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self.assertRaises(TypeError, zip)
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self.assertRaises(TypeError, zip, None)
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self.assertRaises(TypeError, zip, range(10), 42)
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self.assertRaises(TypeError, zip, range(10), zip)
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self.assertEqual(zip(IteratingSequenceClass(3)),
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[(0,), (1,), (2,)])
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self.assertEqual(zip(SequenceClass(3)),
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[(0,), (1,), (2,)])
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d = {"one": 1, "two": 2, "three": 3}
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self.assertEqual(d.items(), zip(d, d.itervalues()))
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# Generate all ints starting at constructor arg.
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class IntsFrom:
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def __init__(self, start):
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self.i = start
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def __iter__(self):
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return self
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def next(self):
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i = self.i
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self.i = i+1
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return i
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f = open(TESTFN, "w")
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try:
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f.write("a\n" "bbb\n" "cc\n")
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finally:
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f.close()
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f = open(TESTFN, "r")
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try:
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self.assertEqual(zip(IntsFrom(0), f, IntsFrom(-100)),
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[(0, "a\n", -100),
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(1, "bbb\n", -99),
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(2, "cc\n", -98)])
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finally:
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f.close()
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try:
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unlink(TESTFN)
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except OSError:
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pass
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# Test reduces()'s use of iterators.
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def test_builtin_reduce(self):
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from operator import add
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self.assertEqual(reduce(add, SequenceClass(5)), 10)
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self.assertEqual(reduce(add, SequenceClass(5), 42), 52)
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self.assertRaises(TypeError, reduce, add, SequenceClass(0))
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self.assertEqual(reduce(add, SequenceClass(0), 42), 42)
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self.assertEqual(reduce(add, SequenceClass(1)), 0)
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self.assertEqual(reduce(add, SequenceClass(1), 42), 42)
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d = {"one": 1, "two": 2, "three": 3}
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self.assertEqual(reduce(add, d), "".join(d.keys()))
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def test_unicode_join_endcase(self):
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# This class inserts a Unicode object into its argument's natural
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# iteration, in the 3rd position.
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class OhPhooey:
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def __init__(self, seq):
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self.it = iter(seq)
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self.i = 0
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def __iter__(self):
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return self
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def next(self):
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i = self.i
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self.i = i+1
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if i == 2:
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return u"fooled you!"
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return self.it.next()
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f = open(TESTFN, "w")
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try:
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f.write("a\n" + "b\n" + "c\n")
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finally:
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f.close()
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f = open(TESTFN, "r")
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# Nasty: string.join(s) can't know whether unicode.join() is needed
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# until it's seen all of s's elements. But in this case, f's
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# iterator cannot be restarted. So what we're testing here is
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# whether string.join() can manage to remember everything it's seen
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# and pass that on to unicode.join().
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try:
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got = " - ".join(OhPhooey(f))
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self.assertEqual(got, u"a\n - b\n - fooled you! - c\n")
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finally:
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f.close()
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try:
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unlink(TESTFN)
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except OSError:
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pass
|
|
|
|
# Test iterators with 'x in y' and 'x not in y'.
|
|
def test_in_and_not_in(self):
|
|
for sc5 in IteratingSequenceClass(5), SequenceClass(5):
|
|
for i in range(5):
|
|
self.assert_(i in sc5)
|
|
for i in "abc", -1, 5, 42.42, (3, 4), [], {1: 1}, 3-12j, sc5:
|
|
self.assert_(i not in sc5)
|
|
|
|
self.assertRaises(TypeError, lambda: 3 in 12)
|
|
self.assertRaises(TypeError, lambda: 3 not in map)
|
|
|
|
d = {"one": 1, "two": 2, "three": 3, 1j: 2j}
|
|
for k in d:
|
|
self.assert_(k in d)
|
|
self.assert_(k not in d.itervalues())
|
|
for v in d.values():
|
|
self.assert_(v in d.itervalues())
|
|
self.assert_(v not in d)
|
|
for k, v in d.iteritems():
|
|
self.assert_((k, v) in d.iteritems())
|
|
self.assert_((v, k) not in d.iteritems())
|
|
|
|
f = open(TESTFN, "w")
|
|
try:
|
|
f.write("a\n" "b\n" "c\n")
|
|
finally:
|
|
f.close()
|
|
f = open(TESTFN, "r")
|
|
try:
|
|
for chunk in "abc":
|
|
f.seek(0, 0)
|
|
self.assert_(chunk not in f)
|
|
f.seek(0, 0)
|
|
self.assert_((chunk + "\n") in f)
|
|
finally:
|
|
f.close()
|
|
try:
|
|
unlink(TESTFN)
|
|
except OSError:
|
|
pass
|
|
|
|
# Test iterators with operator.countOf (PySequence_Count).
|
|
def test_countOf(self):
|
|
from operator import countOf
|
|
self.assertEqual(countOf([1,2,2,3,2,5], 2), 3)
|
|
self.assertEqual(countOf((1,2,2,3,2,5), 2), 3)
|
|
self.assertEqual(countOf("122325", "2"), 3)
|
|
self.assertEqual(countOf("122325", "6"), 0)
|
|
|
|
self.assertRaises(TypeError, countOf, 42, 1)
|
|
self.assertRaises(TypeError, countOf, countOf, countOf)
|
|
|
|
d = {"one": 3, "two": 3, "three": 3, 1j: 2j}
|
|
for k in d:
|
|
self.assertEqual(countOf(d, k), 1)
|
|
self.assertEqual(countOf(d.itervalues(), 3), 3)
|
|
self.assertEqual(countOf(d.itervalues(), 2j), 1)
|
|
self.assertEqual(countOf(d.itervalues(), 1j), 0)
|
|
|
|
f = open(TESTFN, "w")
|
|
try:
|
|
f.write("a\n" "b\n" "c\n" "b\n")
|
|
finally:
|
|
f.close()
|
|
f = open(TESTFN, "r")
|
|
try:
|
|
for letter, count in ("a", 1), ("b", 2), ("c", 1), ("d", 0):
|
|
f.seek(0, 0)
|
|
self.assertEqual(countOf(f, letter + "\n"), count)
|
|
finally:
|
|
f.close()
|
|
try:
|
|
unlink(TESTFN)
|
|
except OSError:
|
|
pass
|
|
|
|
# Test iterators on RHS of unpacking assignments.
|
|
def test_unpack_iter(self):
|
|
a, b = 1, 2
|
|
self.assertEqual((a, b), (1, 2))
|
|
|
|
a, b, c = IteratingSequenceClass(3)
|
|
self.assertEqual((a, b, c), (0, 1, 2))
|
|
|
|
try: # too many values
|
|
a, b = IteratingSequenceClass(3)
|
|
except ValueError:
|
|
pass
|
|
else:
|
|
self.fail("should have raised ValueError")
|
|
|
|
try: # not enough values
|
|
a, b, c = IteratingSequenceClass(2)
|
|
except ValueError:
|
|
pass
|
|
else:
|
|
self.fail("should have raised ValueError")
|
|
|
|
try: # not iterable
|
|
a, b, c = len
|
|
except TypeError:
|
|
pass
|
|
else:
|
|
self.fail("should have raised TypeError")
|
|
|
|
a, b, c = {1: 42, 2: 42, 3: 42}.itervalues()
|
|
self.assertEqual((a, b, c), (42, 42, 42))
|
|
|
|
f = open(TESTFN, "w")
|
|
lines = ("a\n", "bb\n", "ccc\n")
|
|
try:
|
|
for line in lines:
|
|
f.write(line)
|
|
finally:
|
|
f.close()
|
|
f = open(TESTFN, "r")
|
|
try:
|
|
a, b, c = f
|
|
self.assertEqual((a, b, c), lines)
|
|
finally:
|
|
f.close()
|
|
try:
|
|
unlink(TESTFN)
|
|
except OSError:
|
|
pass
|
|
|
|
(a, b), (c,) = IteratingSequenceClass(2), {42: 24}
|
|
self.assertEqual((a, b, c), (0, 1, 42))
|
|
|
|
run_unittest(TestCase)
|