Viewing file:  test_enumerate.py (7.16 KB) -rw-r--r--
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import unittest
import sys
from test import support
class G:
'Sequence using __getitem__'
def __init__(self, seqn):
self.seqn = seqn
def __getitem__(self, i):
return self.seqn[i]
class I:
'Sequence using iterator protocol'
def __init__(self, seqn):
self.seqn = seqn
self.i = 0
def __iter__(self):
return self
def __next__(self):
if self.i >= len(self.seqn): raise StopIteration
v = self.seqn[self.i]
self.i += 1
return v
class Ig:
'Sequence using iterator protocol defined with a generator'
def __init__(self, seqn):
self.seqn = seqn
self.i = 0
def __iter__(self):
for val in self.seqn:
yield val
class X:
'Missing __getitem__ and __iter__'
def __init__(self, seqn):
self.seqn = seqn
self.i = 0
def __next__(self):
if self.i >= len(self.seqn): raise StopIteration
v = self.seqn[self.i]
self.i += 1
return v
class E:
'Test propagation of exceptions'
def __init__(self, seqn):
self.seqn = seqn
self.i = 0
def __iter__(self):
return self
def __next__(self):
3 // 0
class N:
'Iterator missing __next__()'
def __init__(self, seqn):
self.seqn = seqn
self.i = 0
def __iter__(self):
return self
class EnumerateTestCase(unittest.TestCase):
enum = enumerate
seq, res = 'abc', [(0,'a'), (1,'b'), (2,'c')]
def test_basicfunction(self):
self.assertEqual(type(self.enum(self.seq)), self.enum)
e = self.enum(self.seq)
self.assertEqual(iter(e), e)
self.assertEqual(list(self.enum(self.seq)), self.res)
self.enum.__doc__
def test_getitemseqn(self):
self.assertEqual(list(self.enum(G(self.seq))), self.res)
e = self.enum(G(''))
self.assertRaises(StopIteration, next, e)
def test_iteratorseqn(self):
self.assertEqual(list(self.enum(I(self.seq))), self.res)
e = self.enum(I(''))
self.assertRaises(StopIteration, next, e)
def test_iteratorgenerator(self):
self.assertEqual(list(self.enum(Ig(self.seq))), self.res)
e = self.enum(Ig(''))
self.assertRaises(StopIteration, next, e)
def test_noniterable(self):
self.assertRaises(TypeError, self.enum, X(self.seq))
def test_illformediterable(self):
self.assertRaises(TypeError, self.enum, N(self.seq))
def test_exception_propagation(self):
self.assertRaises(ZeroDivisionError, list, self.enum(E(self.seq)))
def test_argumentcheck(self):
self.assertRaises(TypeError, self.enum) # no arguments
self.assertRaises(TypeError, self.enum, 1) # wrong type (not iterable)
self.assertRaises(TypeError, self.enum, 'abc', 'a') # wrong type
self.assertRaises(TypeError, self.enum, 'abc', 2, 3) # too many arguments
@support.cpython_only
def test_tuple_reuse(self):
# Tests an implementation detail where tuple is reused
# whenever nothing else holds a reference to it
self.assertEqual(len(set(map(id, list(enumerate(self.seq))))), len(self.seq))
self.assertEqual(len(set(map(id, enumerate(self.seq)))), min(1,len(self.seq)))
class MyEnum(enumerate):
pass
class SubclassTestCase(EnumerateTestCase):
enum = MyEnum
class TestEmpty(EnumerateTestCase):
seq, res = '', []
class TestBig(EnumerateTestCase):
seq = range(10,20000,2)
res = list(zip(range(20000), seq))
class TestReversed(unittest.TestCase):
def test_simple(self):
class A:
def __getitem__(self, i):
if i < 5:
return str(i)
raise StopIteration
def __len__(self):
return 5
for data in 'abc', range(5), tuple(enumerate('abc')), A(), range(1,17,5):
self.assertEqual(list(data)[::-1], list(reversed(data)))
self.assertRaises(TypeError, reversed, {})
# don't allow keyword arguments
self.assertRaises(TypeError, reversed, [], a=1)
def test_range_optimization(self):
x = range(1)
self.assertEqual(type(reversed(x)), type(iter(x)))
@support.cpython_only
def test_len(self):
# This is an implementation detail, not an interface requirement
from test.test_iterlen import len
for s in ('hello', tuple('hello'), list('hello'), range(5)):
self.assertEqual(len(reversed(s)), len(s))
r = reversed(s)
list(r)
self.assertEqual(len(r), 0)
class SeqWithWeirdLen:
called = False
def __len__(self):
if not self.called:
self.called = True
return 10
raise ZeroDivisionError
def __getitem__(self, index):
return index
r = reversed(SeqWithWeirdLen())
self.assertRaises(ZeroDivisionError, len, r)
def test_gc(self):
class Seq:
def __len__(self):
return 10
def __getitem__(self, index):
return index
s = Seq()
r = reversed(s)
s.r = r
def test_args(self):
self.assertRaises(TypeError, reversed)
self.assertRaises(TypeError, reversed, [], 'extra')
def test_bug1229429(self):
# this bug was never in reversed, it was in
# PyObject_CallMethod, and reversed_new calls that sometimes.
if not hasattr(sys, "getrefcount"):
return
def f():
pass
r = f.__reversed__ = object()
rc = sys.getrefcount(r)
for i in range(10):
try:
reversed(f)
except TypeError:
pass
else:
self.fail("non-callable __reversed__ didn't raise!")
self.assertEqual(rc, sys.getrefcount(r))
def test_objmethods(self):
# Objects must have __len__() and __getitem__() implemented.
class NoLen(object):
def __getitem__(self): return 1
nl = NoLen()
self.assertRaises(TypeError, reversed, nl)
class NoGetItem(object):
def __len__(self): return 2
ngi = NoGetItem()
self.assertRaises(TypeError, reversed, ngi)
class EnumerateStartTestCase(EnumerateTestCase):
def test_basicfunction(self):
e = self.enum(self.seq)
self.assertEqual(iter(e), e)
self.assertEqual(list(self.enum(self.seq)), self.res)
class TestStart(EnumerateStartTestCase):
enum = lambda self, i: enumerate(i, start=11)
seq, res = 'abc', [(11, 'a'), (12, 'b'), (13, 'c')]
class TestLongStart(EnumerateStartTestCase):
enum = lambda self, i: enumerate(i, start=sys.maxsize+1)
seq, res = 'abc', [(sys.maxsize+1,'a'), (sys.maxsize+2,'b'),
(sys.maxsize+3,'c')]
def test_main(verbose=None):
support.run_unittest(__name__)
# verify reference counting
if verbose and hasattr(sys, "gettotalrefcount"):
counts = [None] * 5
for i in range(len(counts)):
support.run_unittest(__name__)
counts[i] = sys.gettotalrefcount()
print(counts)
if __name__ == "__main__":
test_main(verbose=True)
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