单向队列：数据先进先出
双向队列：可进可出
双向队列部分源码：
1 class deque(object): 2 """ 3 deque([iterable[, maxlen]]) --> deque object 4 5 Build an ordered collection with optimized access from its endpoints. 6 """ 7 def append(self, *args, **kwargs): # real signature unknown 8 """ Add an element to the right side of the deque. """ 9 pass 10 11 def appendleft(self, *args, **kwargs): # real signature unknown 12 """ Add an element to the left side of the deque. """ 13 pass 14 15 def clear(self, *args, **kwargs): # real signature unknown 16 """ Remove all elements from the deque. """ 17 pass 18 19 def count(self, value): # real signature unknown; restored from __doc__ 20 """ D.count(value) -> integer -- return number of occurrences of value """ 21 return 0 22 23 def extend(self, *args, **kwargs): # real signature unknown 24 """ Extend the right side of the deque with elements from the iterable """ 25 pass 26 27 def extendleft(self, *args, **kwargs): # real signature unknown 28 """ Extend the left side of the deque with elements from the iterable """ 29 pass 30 31 def pop(self, *args, **kwargs): # real signature unknown 32 """ Remove and return the rightmost element. """ 33 pass 34 35 def popleft(self, *args, **kwargs): # real signature unknown 36 """ Remove and return the leftmost element. """ 37 pass 38 39 def remove(self, value): # real signature unknown; restored from __doc__ 40 """ D.remove(value) -- remove first occurrence of value. """ 41 pass 42 43 def reverse(self): # real signature unknown; restored from __doc__ 44 """ D.reverse() -- reverse *IN PLACE* """ 45 pass 46 47 def rotate(self, *args, **kwargs): # real signature unknown 48 """ Rotate the deque n steps to the right (default n=1). If n is negative, rotates left. """ 49 pass
1 #练习验证
2 import collections
3 aa = collections.deque() #双向队列
4 aa.append("1") #在右边添加
5 aa.appendleft("10") #在左边添加
6 aa.appendleft("1")
7 bb = aa.count("1") #统计指定字符出现的次数
8 print(aa)
9 print(bb)
10 print(aa.clear()) #清空队列，返回None
11 aa.extend(["rr","hh","kk"]) #向右扩展
12 aa.extendleft(["r1r","h1h","kk1"]) #向左扩展
13 print(aa)
14 print(aa.pop()) #不加参数默认移除最后一个，
15 print(aa.popleft()) #不加参数默认移除最左边一个
16 aa.remove(‘rr‘) #移除指定值
17 print(aa)
18 aa.reverse()
19 print(aa) #翻转
20 aa.rotate(1) #把后面的几个移到前面去
21 print(aa)
22
23 #执行结果：
24 deque([‘1‘, ‘10‘, ‘1‘])
25 2
26 None
27 deque([‘kk1‘, ‘h1h‘, ‘r1r‘, ‘rr‘, ‘hh‘, ‘kk‘])
28 kk
29 kk1
30 deque([‘h1h‘, ‘r1r‘, ‘hh‘])
31 deque([‘hh‘, ‘r1r‘, ‘h1h‘])
32 deque([‘h1h‘, ‘hh‘, ‘r1r‘])
单向队列部分源码：
1 def join(self):
2 ‘‘‘Blocks until all items in the Queue have been gotten and processed.
3
4 The count of unfinished tasks goes up whenever an item is added to the
5 queue. The count goes down whenever a consumer thread calls task_done()
6 to indicate the item was retrieved and all work on it is complete.
7
8 When the count of unfinished tasks drops to zero, join() unblocks.
9 ‘‘‘
10 with self.all_tasks_done:
11 while self.unfinished_tasks:
12 self.all_tasks_done.wait()
13
14 def qsize(self):
15 ‘‘‘Return the approximate size of the queue (not reliable!).‘‘‘
16 with self.mutex:
17 return self._qsize()
18
19 def empty(self):
20 ‘‘‘Return True if the queue is empty, False otherwise (not reliable!).
21
22 This method is likely to be removed at some point. Use qsize() == 0
23 as a direct substitute, but be aware that either approach risks a race
24 condition where a queue can grow before the result of empty() or
25 qsize() can be used.
26
27 To create code that needs to wait for all queued tasks to be
28 completed, the preferred technique is to use the join() method.
29 ‘‘‘
30 with self.mutex:
31 return not self._qsize()
32
33 def full(self):
34 ‘‘‘Return True if the queue is full, False otherwise (not reliable!).
35
36 This method is likely to be removed at some point. Use qsize() >= n
37 as a direct substitute, but be aware that either approach risks a race
38 condition where a queue can shrink before the result of full() or
39 qsize() can be used.
40 ‘‘‘
41 with self.mutex:
42 return 0 < self.maxsize <= self._qsize()
43
44 def put(self, item, block=True, timeout=None):
45 ‘‘‘Put an item into the queue.
46
47 If optional args ‘block‘ is true and ‘timeout‘ is None (the default),
48 block if necessary until a free slot is available. If ‘timeout‘ is
49 a non-negative number, it blocks at most ‘timeout‘ seconds and raises
50 the Full exception if no free slot was available within that time.
51 Otherwise (‘block‘ is false), put an item on the queue if a free slot
52 is immediately available, else raise the Full exception (‘timeout‘
53 is ignored in that case).
54 ‘‘‘
55 with self.not_full:
56 if self.maxsize > 0:
57 if not block:
58 if self._qsize() >= self.maxsize:
59 raise Full
60 elif timeout is None:
61 while self._qsize() >= self.maxsize:
62 self.not_full.wait()
63 elif timeout < 0:
64 raise ValueError("‘timeout‘ must be a non-negative number")
65 else:
66 endtime = time() + timeout
67 while self._qsize() >= self.maxsize:
68 remaining = endtime - time()
69 if remaining <= 0.0:
70 raise Full
71 self.not_full.wait(remaining)
72 self._put(item)
73 self.unfinished_tasks += 1
74 self.not_empty.notify()
75
76 def get(self, block=True, timeout=None):
77 ‘‘‘Remove and return an item from the queue.
78
79 If optional args ‘block‘ is true and ‘timeout‘ is None (the default),
80 block if necessary until an item is available. If ‘timeout‘ is
81 a non-negative number, it blocks at most ‘timeout‘ seconds and raises
82 the Empty exception if no item was available within that time.
83 Otherwise (‘block‘ is false), return an item if one is immediately
84 available, else raise the Empty exception (‘timeout‘ is ignored
85 in that case).
86 ‘‘‘
87 with self.not_empty:
88 if not block:
89 if not self._qsize():
90 raise Empty
91 elif timeout is None:
92 while not self._qsize():
93 self.not_empty.wait()
94 elif timeout < 0:
95 raise ValueError("‘timeout‘ must be a non-negative number")
96 else:
97 endtime = time() + timeout
98 while not self._qsize():
99 remaining = endtime - time()
100 if remaining <= 0.0:
101 raise Empty
102 self.not_empty.wait(remaining)
103 item = self._get()
104 self.not_full.notify()
105 return item
106
107 def put_nowait(self, item):
108 ‘‘‘Put an item into the queue without blocking.
109
110 Only enqueue the item if a free slot is immediately available.
111 Otherwise raise the Full exception.
112 ‘‘‘
113 return self.put(item, block=False)
114
115 def get_nowait(self):
116 ‘‘‘Remove and return an item from the queue without blocking.
117
118 Only get an item if one is immediately available. Otherwise
119 raise the Empty exception.
120 ‘‘‘
121 return self.get(block=False)
122
123 # Override these methods to implement other queue organizations
124 # (e.g. stack or priority queue).
125 # These will only be called with appropriate locks held
126
127 # Initialize the queue representation
1 #练习
2 import queue
3 q = queue.Queue()
4 q.put("123") #加入队列
5 q.put("345")
6 print(q.qsize()) #计算加入队列的数据个数
7 print(q.get()) #取队列数据（先进先出）
8
9 #执行结果
10 2
11 123
时间： 2024-10-18 05:31:37