From 384c407a265ac44d15eecdd339bb154147cda4f8 Mon Sep 17 00:00:00 2001 From: AmirSoroush Date: Mon, 31 Jul 2023 05:07:35 +0300 Subject: [PATCH] Enhance the implementation of Queue using list (#8608) * enhance the implementation of queue using list * enhance readability of queue_on_list.py * rename 'queue_on_list' to 'queue_by_list' to match the class name --- data_structures/queue/queue_by_list.py | 141 +++++++++++++++++++++++++ data_structures/queue/queue_on_list.py | 52 --------- 2 files changed, 141 insertions(+), 52 deletions(-) create mode 100644 data_structures/queue/queue_by_list.py delete mode 100644 data_structures/queue/queue_on_list.py diff --git a/data_structures/queue/queue_by_list.py b/data_structures/queue/queue_by_list.py new file mode 100644 index 000000000..4b05be9fd --- /dev/null +++ b/data_structures/queue/queue_by_list.py @@ -0,0 +1,141 @@ +"""Queue represented by a Python list""" + +from collections.abc import Iterable +from typing import Generic, TypeVar + +_T = TypeVar("_T") + + +class QueueByList(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(iterable or []) + + 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 + """ + + return len(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)) + """ + + return f"Queue({tuple(self.entries)})" + + def put(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) + + def get(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 + """ + + if not self.entries: + raise IndexError("Queue is empty") + return self.entries.pop(0) + + def rotate(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 _ in range(rotation): + put(get(0)) + + def get_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 + """ + + return self.entries[0] + + +if __name__ == "__main__": + from doctest import testmod + + testmod() diff --git a/data_structures/queue/queue_on_list.py b/data_structures/queue/queue_on_list.py deleted file mode 100644 index 71fca6b2f..000000000 --- a/data_structures/queue/queue_on_list.py +++ /dev/null @@ -1,52 +0,0 @@ -"""Queue represented by a Python list""" - - -class Queue: - def __init__(self): - self.entries = [] - self.length = 0 - self.front = 0 - - def __str__(self): - printed = "<" + str(self.entries)[1:-1] + ">" - return printed - - """Enqueues {@code item} - @param item - item to enqueue""" - - def put(self, item): - self.entries.append(item) - self.length = self.length + 1 - - """Dequeues {@code item} - @requirement: |self.length| > 0 - @return dequeued - item that was dequeued""" - - def get(self): - self.length = self.length - 1 - dequeued = self.entries[self.front] - # self.front-=1 - # self.entries = self.entries[self.front:] - self.entries = self.entries[1:] - return dequeued - - """Rotates the queue {@code rotation} times - @param rotation - number of times to rotate queue""" - - def rotate(self, rotation): - for _ in range(rotation): - self.put(self.get()) - - """Enqueues {@code item} - @return item at front of self.entries""" - - def get_front(self): - return self.entries[0] - - """Returns the length of this.entries""" - - def size(self): - return self.length