def test_stacked_dict_with_newpop():
'''Test that stacked.pop has the same semantics has dict.pop.'''
from xoutil.collections import StackedDict
sd = StackedDict(a='level-0', b=1)
assert sd.pop('a') == 'level-0'
assert sd.pop('non', sd) is sd
try:
sd.pop('non')
except KeyError:
pass
else:
assert False, 'Should have raised a KeyError'
def test_stacked_dict():
from xoutil.collections import StackedDict
sd = StackedDict(a='level-0')
assert sd.peek() == dict(a='level-0')
sd.push_level(a=1, b=2, c=10)
assert sd.level == 1
assert sd.peek() == dict(a=1, b=2, c=10)
sd.push_level(b=4, c=5)
assert sd.peek() == dict(b=4, c=5)
assert sd.level == 2
assert sd['b'] == 4
assert sd['a'] == 1
assert sd['c'] == 5
assert len(sd) == 3
del sd['c']
try:
del sd['c']
assert False, 'Should have raise KeyError'
except KeyError:
pass
except:
assert False, 'Should have raise KeyError'
assert sd.pop_level() == {'b': 4}
assert sd['b'] == 2
assert sd['a'] == 1
assert len(sd) == 3
sd.pop_level()
assert sd['a'] == 'level-0'
try:
sd.pop_level()
assert False, ('Level 0 cannot be poped. '
'It should have raised a TypeError')
except TypeError:
pass
except:
assert False, ('Level 0 cannot be poped. '
'It should have raised a TypeError')
