def test_push_back(self):
dq = LinkedDeque()
dq.push_back('A')
assert dq.length() == 1
assert dq.front() == 'A'
dq.push_back('B')
assert dq.length() == 2
assert dq.front() == 'A'
dq.push_back('C')
assert dq.length() == 3
assert dq.front() == 'A'
assert dq.is_empty() == False
def test_pop_back(self):
dq = LinkedDeque(['A', 'B', 'C'])
assert dq.length() == 3
assert dq.front() == 'A'
dq.pop_back()
assert dq.length() == 2
assert dq.front() == 'A'
dq.pop_back()
assert dq.length() == 1
assert dq.front() == 'A'
assert dq.is_empty() == False
dq.pop_back()
assert dq.length() == 0
assert dq.front() == None
assert dq.is_empty() == True
def test_push_back(self):
q = LinkedDeque()
q.push_back("A")
assert q.length() == 1
q.push_back("B")
assert q.length() == 2
assert q.front() == "A"
assert q.back() == "B"
def test_init(self):
dq = LinkedDeque()
assert dq.front() is None
assert dq.length() == 0
assert dq.is_empty() is True
def test_init_with_list(self):
dq = LinkedDeque(['A', 'B', 'C'])
assert dq.front() == 'A'
assert dq.length() == 3
assert dq.is_empty() is False
def test_front(self):
q = LinkedDeque()
assert q.front() is None