def full_list():
new_list = DoubleLink([1, 2, 3])
return new_list
def test_multi_value_list_with_parens():
"""Test that you can create a list with a string of parens."""
new_list = DoubleLink(')()()()')
assert new_list.head.value == ')'
def test_create_empty_dll():
"""Test whether we create an empty list."""
new_list = DoubleLink()
assert new_list._length is 0
def test_create_one_value_list():
"""Test that you can create list with one value."""
new_list = DoubleLink(')')
assert new_list._length == 1
def balanced_list():
new_list = DoubleLink(')()()()(')
return new_list
def test_create_list_raise_error():
"""Test that TypeError is raised when you init with noniterable."""
with pytest.raises(TypeError):
new_dll = DoubleLink(iterable=123456)
def test_balanced_tail_closed_returns_0():
"""Test that a list with a closed tail returns 0."""
new_list = DoubleLink(')()(')
assert new_list.tail.value == ')'
assert new_list.balanced() == 0
def open_list():
new_list = DoubleLink(')(()(')
return new_list
def test_balanced_tail_open():
"""Test that a list with an open tail returns 1."""
new_list = DoubleLink('(()(')
assert new_list.tail.value == '('
assert new_list.balanced() == 1
def test_balanced_empty_list():
"""Test that an empty list returns a value error."""
new_list = DoubleLink()
with pytest.raises(ValueError):
new_list.balanced()
def broken_list():
new_list = DoubleLink(')())(')
return new_list
def test_balanced_first_node_closed_paren():
"""Check that balanced returns -1 when head is ')'."""
new_list = DoubleLink('()')
assert new_list.balanced() == -1
def test_push_tail_node_empty_list():
"""Test that when you push to an empty list, the head is also the tail."""
new_list = DoubleLink()
new_list.push(15)
assert new_list.tail.value == 15