PYTHON学习之路_PYTHON基础（10）

时间：2021-12-28 13:39:47

学习内容：

Python进程与线程

1、线程及线程类

2、线程守护

3、线程等待

4、线程锁

5、信号量

6、timer用法

7、队列

8、事件驱动

9、生产者消费者模型

10、进程及进程同步

11、进程池

12、递归锁

13、进程间通讯

一、线程及线程类

import threading
import time

class MyThread(threading.Thread):
    def __init__(self,num):
        threading.Thread.__init__(self)
        self.num = num

    def run(self):
        print ('running on number :%s'%self.num)
        print ('threading_act',threading.active_count() )
        print ('threading_cur:',threading.current_thread())
        time.sleep(3)

if __name__ == '__main__':
    t1 = MyThread('alex')
    t2 = MyThread('json')
    t1.start()
    t2.start()
    print (t1.getName())
    print (t2.getName())
    print('threading_c:', threading.current_thread())

二、线程守护

import threading
import time

def run(n):
    time.sleep(1)
    print ("thread",n)
t_list = []
for  i in  range(10):
    t = threading.Thread(target=run,args=(i,))
    t.setDaemon(True)
    t.start()
    t_list.append(t)
print (t_list)
print ('----main thread----')

三、线程等待

import threading
import time
def run(n):
    time.sleep(1)
    print ("thread",n)
t_list = []
for  i in  range(10):
    t = threading.Thread(target=run,args=(i,))
    t.start()
    t_list.append(t)
for t in t_list:
    print ('t_list:',t)
    t.join()  #t.wait
print ('----main thread----')

四、线程锁

import  threading
import time

l = threading.Lock()
def run(n):
    global  num
    l.acquire()  #获取锁
    num += 1
    time.sleep(1)
    l.release()  #释放锁
    print(num)
    time.sleep(1)
    #print("thread",n)
def run2():
    count = 0
    while num < 9:
        print ('---------',count)
        count += 1
num = 0
t_list = []
for i in range(10):
    t = threading.Thread(target=run, args=(i,))
    t.start()
    t_list.append(t)
t2 = threading.Thread(target=run2)
t2.start()
for t in t_list:
    t.join()
print("--main thread---")
print(num)

五、信号量（多线程）

import threading, time

def run3(n):
    semaphore.acquire()
    time.sleep(1)
    print('--------between run1 and run2-----',n)
    semaphore.release()
if __name__ == '__main__':
    num, num2 = 0, 0
    semaphore = threading.BoundedSemaphore(5)
    for i in range(20):
        t = threading.Thread(target=run3,args=(i,))
        t.start()
while threading.active_count() != 1:
    pass
    #print('active_count',threading.active_count())
else:
    print('----all threads done---')
    print(num, num2)

六、timer用法

import threading
import time
def hello():
    print("hello, world")
t1 = time.time()
t = threading.Timer(3.0, hello)
t.start()  # after 30 seconds, "hello, world" will be printed
t.join()
t2 = time.time()
change_time = t2 - t1
print (change_time)

七、队列

q = queue.Queue(maxsize=2)
# q.put(1)
# q.put(2)
# q.put(9)
# q.put('alex')
# q.put_nowait('jack')
# q.mutex
# q.qsize()
# q.join()
# q.task_done()
# q.empty()   #判断队列是否为空
# q.full()    #判断队列是否满
q=queue.LifoQueue()
q=queue.PriorityQueue()
q.put([4,'40'])
q.put([5,'50'])
q.put([1,'100'])
q.put([2,'20'])
print(q.get())
print(q.get())
print(q.get())
print(q.get())

八、事件驱动

import  threading
import time
import random
def lighter():
    count = 0
    while True:
        if count < 30:
            if not event_flag.is_set():
                event_flag.set()
            print ('\033[32m----green light----\033[0m:%s'%count)
        elif count < 35:
            print('\033[33m----green light----\033[0m:%s' %count)
        elif count < 60:
            if event_flag.is_set():
                event_flag.clear()
            print('\033[31m----green light----\033[0m:%s' %count)
        else:
            count = 0
        count += 1
        time.sleep(0.2)
def car(n):
    while True:
        event_flag.wait()
        print ('car [%s] is running throught the lighter...'%n)
        time.sleep(random.randint(0, 3))
event_flag = threading.Event()
light_flag = threading.Thread(target=lighter)
light_flag.start()
car_list = ['宝马','大奔','路虎','兰博基尼','夏利']
for n in car_list:
    car_flag = threading.Thread(target=car,args=(n,))
    car_flag.start()

九、生产者消费者模型

import threading
import queue
import time
def consumer(name):
    while True:
        print ('%s 取到 骨头 【%s】,并吃了它。'%(name,q.get()))
        time.sleep(0.5)
        q.task_done()   #回执
def producer(name):
    count = 0
    #while q.qsize() < 6:
    for i in range (10):
        print ('%s生成了骨头 %s！'%(name,count) )
        q.put(count)
        count +=1
        time.sleep(0.3)
    q.join()
q = queue.Queue(maxsize=5)
p = threading.Thread(target=producer,args=('Alex',))
p2 = threading.Thread(target=producer,args=('shuangmei',))
c = threading.Thread(target=consumer,args=('spider',))
p.start()
p2.start()
c.start()

十、进程及进程同步

from multiprocessing import Process, Lock
#作用：输出到屏幕出现乱行，加锁保证不串行

def f(l, i):
    l.acquire()
    try:
        print('hello world', i)
    finally:
        l.release()
if __name__ == '__main__':
    lock = Lock()
    for num in range(10):
        Process(target=f, args=(lock, num)).start()

十一、进程池

from multiprocessing import Process, Lock,Pool
import  time
import os
#作用：输出到屏幕出现乱行，加锁保证不串行

def f(i):
    #l.acquire()
    print('hello world', i)
    print ('-----f:',i,os.getpid())
    time.sleep(4)
    #l.release()
def callback(data):
    print ('exec done---',data)
    print('----callback',data,os.getpid())

if __name__ == '__main__':
    lock = Lock()
    pool = Pool(processes=5)
    for num in range(10):
        #Process(target=f, args=(lock, num)).start()
        #pool.apply_async(func=f, args=(lock,num), callback=Bar)
        pool.apply_async(func=f, args=(num,),callback=callback)
        #apply 不要用，就用apply_async即可
    pool.close()
    pool.join()

十二、递归锁

import threading, time
def run1():
    print("grab the first part data")
    lock.acquire()
    global num
    num += 1
    lock.release()
    return num
def run2():
    print("grab the second part data")
    lock.acquire()
    global num2
    num2 += 1
    lock.release()
    return num2
def run3():
    lock.acquire()
    res = run1()
    print('--------between run1 and run2-----')
    res2 = run2()
    lock.release()
    print(res, res2)
if __name__ == '__main__':
    num, num2 = 0, 0
    lock = threading.RLock()  #若用lock  则死锁
    for i in range(10):
        t = threading.Thread(target=run3)
        t.start()
while threading.active_count() != 1:
    print('active_count',threading.active_count())
else:
    print('----all threads done---')
    print(num, num2)

十三、进程间通讯

from multiprocessing import Process,Queue  #进程的queue
import queue   #线程的queue
def f(q):
    q.put([42, None, 'hello'])
    q.put(123)
if __name__ == '__main__':
    #q=queue.Queue    #线程的队列
    q = Queue()
    p = Process(target=f, args=(q,))
    p.start()
    print(q.get())  # prints "[42, None, 'hello']"
    print (q.get())
    p.join()

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