python 进程间通信

队列Queue模块

管道：subprocess 

stdin stdout stderr

队列：先进先出 自动带锁（暂时未理解）

堆栈：先进后出

队列在多进程的时候不精准

from multiprocessing import Queue
q = Queue(3)

q.put(1111)
q.put(2222)
q.full()
q.put(3333)
# q.put(4444)  # 只能放3个数据，放了4个数据也会阻塞


q1 = q.get()
q2 = q.get()
q3 = q.get()
q.empty()
# q4 = q.get()   # 没有数据就会阻塞，等在那里取数据
# q5 = q.get()
print(q1,q2,q3,)
try:
    q4 = q.get()
    print(q4)
except Exception as e:
    print("no data")

 借助队列实现进程与进程之间的通信

一、主进程同子进程之间的通信

from multiprocessing import Process, Queue
def producer(q):
    q.put("hello world")

if __name__ == "__main__":
    q = Queue()
    p = Process(target=producer, args=(q,))
    p.start()
    print(q.get())
二、子进程与子进程之间的通信

from multiprocessing import Process, Queue

def producer(q):
    q.put("hello world")

def customer(q):

    print(q.get())

if __name__ == "__main__":
    q = Queue()
    p1 = Process(target=producer, args=(q,))
    p2 = Process(target=customer, args=(q,))
    p1.start()
    p2.start()