class Queue(object):
"""Make queue object from doubly-linked list object."""
def __init__(self, val=None):
"""Initialize queue."""
self._container = DoublyLinked(val)
def enqueue(self, val):
"""Push item to queue."""
self._container.append(val)
def dequeue(self):
"""Remove item from head queue and return its value."""
return self._container.pop()
def peek(self):
"""Return next value in queue."""
if self._container.head is self._container._mark:
return None
else:
return self._container.head.get_data()
def size(self):
"""Return the length of the list."""
counter = 0
current_node = self._container.head
while current_node is not self._container._mark:
counter += 1
current_node = current_node.get_next()
return counter
class Queue(object):
"""Make queue object from doubly-linked list object."""
def __init__(self, val=None):
"""Initialize queue."""
self._container = DoublyLinked(val)
def enqueue(self, val):
"""Push item to queue."""
self._container.append(val)
def dequeue(self):
"""Remove item from head queue and return its value."""
return self._container.pop()
def peek(self):
"""Return next value in queue."""
if self._container.head is self._container._mark:
return None
else:
return self._container.head.get_data()
def size(self):
"""Return the length of the list."""
counter = 0
current_node = self._container.head
while current_node is not self._container._mark:
counter += 1
current_node = current_node.get_next()
return counter
def test_pop(li):
"""Test pop function."""
from doubly_linked import DoublyLinked
new_list = DoublyLinked()
new_list.insert(li)
assert new_list.pop() == 'one'
try:
new_list.head.prev_node
except AttributeError:
assert True
def test_insert(li, result):
"""Test insert function."""
from doubly_linked import DoublyLinked
new_list = DoublyLinked()
new_list.insert(li)
new_list.pop()
assert result == 'one'
def test_remove():
from doubly_linked import DoublyLinked
new_list = DoublyLinked()
new_list.insert([1, 2, 3])
new_list.remove(3)
assert new_list.shift() == 2
def test_shift_empty(li):
from doubly_linked import DoublyLinked
new_list = DoublyLinked()
new_list.insert(li)
with pytest.raises(IndexError):
new_list.shift()
def test_shift(li, result):
from doubly_linked import DoublyLinked
new_list = DoublyLinked()
new_list.insert(li)
assert new_list.shift() == result
def test_append(li, result):
from doubly_linked import DoublyLinked
new_list = DoublyLinked()
new_list.insert(li)
new_list.append('four')
assert result == new_list.shift()
def test_new_list():
"""Test list constructor."""
from doubly_linked import DoublyLinked
new_list = DoublyLinked()
assert isinstance(new_list, DoublyLinked)
def __init__(self, val=None):
"""Initialize queue."""
self._container = DoublyLinked(val)
def __init__(self, val=None):
"""Initialize queue."""
self._container = DoublyLinked(val)