进程
一,用函数方法写多进程
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
from multiprocessing import Process import os import time def info(titile): print(title) print('module name',__name__) print('prarent process:',os.getppid) print('process id:',os.getpid) def f(name): info('\033[31;1mfunction f\033[0m') print('hello',name) if __name__=='__main__':#此代码必须要写,否则要报错 info('\033[32;1mmain process line\033[0m') time.sleep(1) p = Process(target=info,argv=('bob',)) p.start() p.join()
1.os.getpid(0#获取进程id
2.os.getppid()#获取父进程id
3.进程之间的关系:
子进程的父进程是主进程,主进程的父进程是运行的进程id,每一进程都有一个父进程,最终会归结到一个根进程。
from mutiprocessing import Process import time import os class Myprocess(Process): def __init__(self,name): super(Myprocess,self).__init__() self.name=name def run(): time.sleep(1) print('hello',self.name,time.ctime()) if __name__=='__main__': p_list=[] for i in range(3): p=Myprocess('alex') p.start() p_list.append(p) for p in p_list: p.join(0 print('end')
三。进程间通信
两种方法:queue,与pipe
from multiprocess import Process,Queue def f(q,n): q.put([42,n,'hello']) #要将队列当作形参传入 if __name__=='__main__': q = Queue() p_list=[] for i in range(3): p = Proces(target=f,argv=(q,i)) p_list.append(p) p.start() print(q.get()) print(q.get()) print(q.get()) for i in range(3): i.join()
from multiprocess import Process,Pipe def f(conn):#conn为管道的一端 conn.send([42,None,'hello']) conn.close() if __name__=='__main__': parent_pipe,childe_pipe=Pipe() p = Process(targe=f,argv=(childe_pipe)) p.start() print(parent_pipe.recv()) p.join()
四.Manager创建的东西可以直接通信
from multiprocess import Process,Manager def f(d,l,i): d[i]=i l.append(i) d['good']='day' if __name__=='__main__': with Manager() as manager: d=manager.dict() l=manager.list() p_list=[] for i in range(10): p = Process(target=f,argv=(d,l,i)) p.start() p_list.append() for i in p_list(): i.join()