def insert(self, index, value):
"""Insert item by index.
Args:
index (int): index for insert
value : value for insert
Raises:
CollectionIsEmptyExeption: if list is empty
IndexError: if index is not valid
"""
if self.is_empty:
raise CollectionIsEmptyExeption(list_is_empty())
if not self.index_valid(index):
raise IndexError(index_out_of_range())
if index == 0:
self.push_front(value)
return
else:
node = Node(value)
previously = self._find_by(index - 1)
node.next = previously.next
previously.next = node
self._size += 1
def dequeue(self):
"""Extract item from queue.
Returns:
item: top item from queue
Raises:
CollectionIsEmptyExeption: if queue is empty
"""
if self._queue.is_empty:
raise CollectionIsEmptyExeption(queue_is_empty())
return self._queue.extract()
def pop(self):
"""Extract item from stack.
Returns:
item: top item from stack
Raises:
CollectionIsEmptyExeption: if stack is empty
"""
if self.is_empty:
raise CollectionIsEmptyExeption(stack_is_empty())
return self._stack.extract()
def front(self):
"""Return (not extract) first item from list.
Returns:
item: first item from list
Raises:
CollectionIsEmptyExeption: if list is empty
"""
if self.is_empty:
raise CollectionIsEmptyExeption(list_is_empty())
return self._head.data
def pop(stack):
"""Extract item from stack.
Args:
stack: stack data structure (created by function make_stack())
Returns:
item: top item from stack
Raises:
CollectionIsEmptyExeption: if stack is empty
"""
if is_empty(stack):
raise CollectionIsEmptyExeption(stack_is_empty())
return _extract(stack)
def dequeue(self):
"""Extract item from queue.
Returns:
item: top item from queue
Raises:
CollectionIsEmptyExeption: if queue is empty
"""
if self._extract_stack.is_empty:
while not self._put_stack.is_empty:
self._extract_stack.push(self._put_stack.pop())
if self._extract_stack.is_empty:
raise CollectionIsEmptyExeption(queue_is_empty())
return self._extract_stack.pop()
def pop_back(self):
"""Return (and extract) last item from list.
Returns:
last_item: last item from list
Raises:
CollectionIsEmptyExeption: if list is empty
"""
if self.is_empty:
raise CollectionIsEmptyExeption(list_is_empty())
penultimate = self._find_by(self._size - 2)
last = penultimate.next
penultimate.next = None
self._size -= 1
return last.data
def pop_front(self):
"""Return (and extract) first item from list.
Returns:
first_element_data: first item from list
Raises:
CollectionIsEmptyExeption: if list is empty
"""
if self.is_empty:
raise CollectionIsEmptyExeption(list_is_empty())
return_value = self._head.data
self._head = self._head.next
self._size -= 1
return return_value
def value_at(self, index):
"""Return (not extract) item by index.
Returns:
item: item from list by index
Args:
index (int): index return item
Raises:
CollectionIsEmptyExeption: if list is empty
IndexError: if index is not valid
"""
if self.is_empty:
raise CollectionIsEmptyExeption(list_is_empty())
if not self.index_valid(index):
raise IndexError(index_out_of_range())
finded = self._find_by(index)
return finded.data
def erase(self, index):
"""Remove element by index from list.
Args:
index (int): index of element for delete
Raises:
CollectionIsEmptyExeption: if list is empty
"""
if self.is_empty:
raise CollectionIsEmptyExeption(self._error_message)
if index == 0:
self.pop_front()
return
if index == self._size - 1:
self.pop_back()
return
previous = self._find_by(index - 1)
deleted = previous.next
previous.next = deleted.next
deleted.next = None
self._size -= 1