def test_shift_with_one_updates_head():
test_dll = Dll()
test_dll.insert(3)
test_dll.shift()
with pytest.raises(ValueError):
test_dll.pop()
def test_dll():
test_dll = Dll()
test_dll.insert('test1')
test_dll.insert('test2')
test_dll.append('test3')
return test_dll
def test_pop_empty():
test_dll = Dll()
with pytest.raises(ValueError):
test_dll.pop()
def test_constructor():
test_dll = Dll()
assert test_dll.head is None
assert test_dll.tail is None
def test_string():
test_list = Dll()
test_list.insert(u'éclaire')
assert str(test_list) == "('\xc3\xa9claire')"
def test_unicode():
test_list = Dll()
test_list.insert(u'ö')
assert unicode(test_list) == u"('ö')"
def test__str__returns_single_output_if_only_one_item():
test_list = Dll()
test_list.insert('test')
assert str(test_list) == "('test')"
def test_remove_last_item():
test_list = Dll()
test_list.insert(5)
test_list.remove(5)
assert test_list.head is None and test_list.tail is None