python的collection系列-双向队列和单向队列

class deque(object):
"""
deque([iterable[, maxlen]]) --> deque object

Build an ordered collection with optimized access from its endpoints.
"""
def append(self, *args, **kwargs): # real signature unknown
""" Add an element to the right side of the deque. """
pass

def appendleft(self, *args, **kwargs): # real signature unknown
""" Add an element to the left side of the deque. """
pass

def clear(self, *args, **kwargs): # real signature unknown
""" Remove all elements from the deque. """
pass

def count(self, value): # real signature unknown; restored from __doc__
""" D.count(value) -> integer -- return number of occurrences of value """
return 0

def extend(self, *args, **kwargs): # real signature unknown
""" Extend the right side of the deque with elements from the iterable """
pass

def extendleft(self, *args, **kwargs): # real signature unknown
""" Extend the left side of the deque with elements from the iterable """
pass

def pop(self, *args, **kwargs): # real signature unknown
""" Remove and return the rightmost element. """
pass

def popleft(self, *args, **kwargs): # real signature unknown
""" Remove and return the leftmost element. """
pass

def remove(self, value): # real signature unknown; restored from __doc__
""" D.remove(value) -- remove first occurrence of value. """
pass

def reverse(self): # real signature unknown; restored from __doc__
""" D.reverse() -- reverse *IN PLACE* """
pass

def rotate(self, *args, **kwargs): # real signature unknown
""" Rotate the deque n steps to the right (default n=1).  If n is negative, rotates left. """
pass

#练习验证
import collections
aa = collections.deque()    #双向队列
aa.append("1")       #在右边添加
aa.appendleft("10")   #在左边添加
aa.appendleft("1")
bb = aa.count("1")     #统计指定字符出现的次数
print(aa)
print(bb)
print(aa.clear())      #清空队列，返回None
aa.extend(["rr","hh","kk"])     #向右扩展
aa.extendleft(["r1r","h1h","kk1"])    #向左扩展
print(aa)
print(aa.pop())     #不加参数默认移除最后一个，
print(aa.popleft())   #不加参数默认移除最左边一个
aa.remove('rr')     #移除指定值
print(aa)
aa.reverse()
print(aa)      #翻转
aa.rotate(1)    #把后面的几个移到前面去
print(aa)

#执行结果：
deque(['1', '10', '1'])
2
None
deque(['kk1', 'h1h', 'r1r', 'rr', 'hh', 'kk'])
kk
kk1
deque(['h1h', 'r1r', 'hh'])
deque(['hh', 'r1r', 'h1h'])
deque(['h1h', 'hh', 'r1r'])

def join(self):
'''Blocks until all items in the Queue have been gotten and processed.

The count of unfinished tasks goes up whenever an item is added to the
queue. The count goes down whenever a consumer thread calls task_done()
to indicate the item was retrieved and all work on it is complete.

When the count of unfinished tasks drops to zero, join() unblocks.
'''
with self.all_tasks_done:
while self.unfinished_tasks:
self.all_tasks_done.wait()

def qsize(self):
'''Return the approximate size of the queue (not reliable!).'''
with self.mutex:
return self._qsize()

def empty(self):
'''Return True if the queue is empty, False otherwise (not reliable!).

This method is likely to be removed at some point.  Use qsize() == 0
as a direct substitute, but be aware that either approach risks a race
condition where a queue can grow before the result of empty() or
qsize() can be used.

To create code that needs to wait for all queued tasks to be
completed, the preferred technique is to use the join() method.
'''
with self.mutex:
return not self._qsize()

def full(self):
'''Return True if the queue is full, False otherwise (not reliable!).

This method is likely to be removed at some point.  Use qsize() >= n
as a direct substitute, but be aware that either approach risks a race
condition where a queue can shrink before the result of full() or
qsize() can be used.
'''
with self.mutex:
return 0 < self.maxsize <= self._qsize()

def put(self, item, block=True, timeout=None):
'''Put an item into the queue.

If optional args 'block' is true and 'timeout' is None (the default),
block if necessary until a free slot is available. If 'timeout' is
a non-negative number, it blocks at most 'timeout' seconds and raises
the Full exception if no free slot was available within that time.
Otherwise ('block' is false), put an item on the queue if a free slot
is immediately available, else raise the Full exception ('timeout'
is ignored in that case).
'''
with self.not_full:
if self.maxsize > 0:
if not block:
if self._qsize() >= self.maxsize:
raise Full
elif timeout is None:
while self._qsize() >= self.maxsize:
self.not_full.wait()
elif timeout < 0:
raise ValueError("'timeout' must be a non-negative number")
else:
endtime = time() + timeout
while self._qsize() >= self.maxsize:
remaining = endtime - time()
if remaining <= 0.0:
raise Full
self.not_full.wait(remaining)
self._put(item)
self.unfinished_tasks += 1
self.not_empty.notify()

def get(self, block=True, timeout=None):
'''Remove and return an item from the queue.

If optional args 'block' is true and 'timeout' is None (the default),
block if necessary until an item is available. If 'timeout' is
a non-negative number, it blocks at most 'timeout' seconds and raises
the Empty exception if no item was available within that time.
Otherwise ('block' is false), return an item if one is immediately
available, else raise the Empty exception ('timeout' is ignored
in that case).
'''
with self.not_empty:
if not block:
if not self._qsize():
raise Empty
elif timeout is None:
while not self._qsize():
self.not_empty.wait()
elif timeout < 0:
raise ValueError("'timeout' must be a non-negative number")
else:
endtime = time() + timeout
while not self._qsize():
remaining = endtime - time()
if remaining <= 0.0:
raise Empty
self.not_empty.wait(remaining)
item = self._get()
self.not_full.notify()
return item

def put_nowait(self, item):
'''Put an item into the queue without blocking.

Only enqueue the item if a free slot is immediately available.
Otherwise raise the Full exception.
'''
return self.put(item, block=False)

def get_nowait(self):
'''Remove and return an item from the queue without blocking.

Only get an item if one is immediately available. Otherwise
raise the Empty exception.
'''
return self.get(block=False)

# Override these methods to implement other queue organizations
# (e.g. stack or priority queue).
# These will only be called with appropriate locks held

# Initialize the queue representation

#练习
import queue
q = queue.Queue()
q.put("123")    #加入队列
q.put("345")
print(q.qsize())   #计算加入队列的数据个数
print(q.get())     #取队列数据（先进先出）

#执行结果
2
123