queue_by_list.py

"""Queue represented by a Python list"""

fromcollections.abcimportIterable
fromtypingimportGeneric, TypeVar

_T=TypeVar("_T")


classQueueByList(Generic[_T]):
def__init__(self, iterable: Iterable[_T] |None=None) ->None:
"""
 >>> QueueByList()
 Queue(())
 >>> QueueByList([10, 20, 30])
 Queue((10, 20, 30))
 >>> QueueByList((i**2 for i in range(1, 4)))
 Queue((1, 4, 9))
 """
self.entries: list[_T] =list(iterableor [])

def__len__(self) ->int:
"""
 >>> len(QueueByList())
 0
 >>> from string import ascii_lowercase
 >>> len(QueueByList(ascii_lowercase))
 26
 >>> queue = QueueByList()
 >>> for i in range(1, 11):
 ... queue.put(i)
 >>> len(queue)
 10
 >>> for i in range(2):
 ... queue.get()
 1
 2
 >>> len(queue)
 8
 """

returnlen(self.entries)

def__repr__(self) ->str:
"""
 >>> queue = QueueByList()
 >>> queue
 Queue(())
 >>> str(queue)
 'Queue(())'
 >>> queue.put(10)
 >>> queue
 Queue((10,))
 >>> queue.put(20)
 >>> queue.put(30)
 >>> queue
 Queue((10, 20, 30))
 """

returnf"Queue({tuple(self.entries)})"

defput(self, item: _T) ->None:
"""Put `item` to the Queue

 >>> queue = QueueByList()
 >>> queue.put(10)
 >>> queue.put(20)
 >>> len(queue)
 2
 >>> queue
 Queue((10, 20))
 """

self.entries.append(item)

defget(self) ->_T:
"""
 Get `item` from the Queue

 >>> queue = QueueByList((10, 20, 30))
 >>> queue.get()
 10
 >>> queue.put(40)
 >>> queue.get()
 20
 >>> queue.get()
 30
 >>> len(queue)
 1
 >>> queue.get()
 40
 >>> queue.get()
 Traceback (most recent call last):
 ...
 IndexError: Queue is empty
 """

ifnotself.entries:
raiseIndexError("Queue is empty")
returnself.entries.pop(0)

defrotate(self, rotation: int) ->None:
"""Rotate the items of the Queue `rotation` times

 >>> queue = QueueByList([10, 20, 30, 40])
 >>> queue
 Queue((10, 20, 30, 40))
 >>> queue.rotate(1)
 >>> queue
 Queue((20, 30, 40, 10))
 >>> queue.rotate(2)
 >>> queue
 Queue((40, 10, 20, 30))
 """

put=self.entries.append
get=self.entries.pop

for_inrange(rotation):
put(get(0))

defget_front(self) ->_T:
"""Get the front item from the Queue

 >>> queue = QueueByList((10, 20, 30))
 >>> queue.get_front()
 10
 >>> queue
 Queue((10, 20, 30))
 >>> queue.get()
 10
 >>> queue.get_front()
 20
 """

returnself.entries[0]


if__name__=="__main__":
fromdoctestimporttestmod

testmod()