def test_dict_iteration_by_keys_using_explicit_call_to_keys_method(ut):
'''
Support the simplest case - one iteration over dictionary using explicit keys() call
For(target=Name(id='k', ctx=Store()),
iter=Call(func=Attribute(value=Name(id='dict_', ctx=Load()),
attr='keys', ctx=Load()), args=[], keywords=[], starargs=None, kwargs=None),
body=[...], orelse=[])
'''
s = '''
dict_ = {1: 2, 3: 4}
def iter_over_dict_keys():
for k in dict_.keys():
# which element returned is undefined
# (actually, it is defined by the order in which keys are iterated,
# which in turn is defined by the hash function, but it's
# too complicated)
# we'll assume that any value can be returned
return dict_.get(k)
new_values = iter_over_dict_keys()
'''
ps.checkString(s)
r = find_in_history('new_values', ps)
ut.assertEqual(3, len(r))
ut.assertNums([2, 4], r[0:2])
ut.assertCont(r[2]) # represents implicitly returned None
def test_dict_default_value():
# exercise
ps.checkString('a = {"a": 1}; b = a.get("b", 2);')
# verify
r = find_in_history('b', ps)
ut.assertEqual(2, len(r))
ut.assertNums([1, 2], r)
def test_tuple_unpack():
# exercise
ps.checkString('''a = {1: 2, 3: 4}
for key, value in a.iteritems():
b = key
c = value''')
# verify
r = find_in_history('key', ps)
ut.assertEqual(2, len(r))
ut.assertNums([1, 3], r)
r = find_in_history('value', ps)
ut.assertEqual(2, len(r))
ut.assertNums([2, 4], r)
