版权声明：本文为博主原创文章，转载请注明作者和出处。https://blog.csdn.net/xq920831/article/details/82752690
开始今天的内容。
多进程multiprocessing
多进程就看看代码吧，理解没问题，和多线程类似，不难。
- 进程queue
from multiprocessing import Process, Queue
import threading
#import queue
# def f(q):
# q.put([42, None, 'hello'])
def f(qq):
print("in child:",qq.qsize())
qq.put([42, None, 'hello'])
if __name__ == '__main__':
q = Queue()
q.put("test123")
#p = threading.Thread(target=f,)
p = Process(target=f, args=(q,))
p.start()
p.join()
print("444",q.get_nowait())
print("444",q.get_nowait())
# prints "[42, None, 'hello']"
#print(q.get()) # prints "[42, None, 'hello']"- 进程getid
from multiprocessing import Process
import os
def info(title):
print(title)
print('module name:', __name__)
print('parent process:', os.getppid()) %父进程id
print('process id:', os.getpid()) %自己的id
print("\n\n")
def f(name):
info('\033[31;1mcalled from child process function f\033[0m')
print('hello', name)
if __name__ == '__main__':
info('\033[32;1mmain process line\033[0m')
p = Process(target=f, args=('bob',))
p.start()
# p.join()- pipes
from multiprocessing import Process, Pipe
def f(conn):
conn.send([42, None, 'hello from child'])
conn.send([42, None, 'hello from child3'])
print("",conn.recv())
conn.close()
if __name__ == '__main__':
parent_conn, child_conn = Pipe()
p = Process(target=f, args=(child_conn,))
p.start()
print("parent",parent_conn.recv()) # prints "[42, None, 'hello']"
print("parent",parent_conn.recv()) # prints "[42, None, 'hello']"
parent_conn.send(" from hshs") # prints "[42, None, 'hello']"
p.join()还有一个：
from multiprocessing import Process, Pipe
def f(conn):
conn.send([42, None, 'hello from child'])
conn.send([42, None, 'hello from child2'])
print("from parent:",conn.recv())
conn.close()
if __name__ == '__main__':
parent_conn, child_conn = Pipe()
p = Process(target=f, args=(child_conn,))
p.start()
print(parent_conn.recv()) # prints "[42, None, 'hello']"
print(parent_conn.recv()) # prints "[42, None, 'hello']"
parent_conn.send("张洋可好") # prints "[42, None, 'hello']"
p.join()- manager
from multiprocessing import Process, Manager
import os
def f(d, l):
d[1] = '1'
d['2'] = 2
d["pid%s" %os.getpid()] = os.getpid()
l.append(1)
print(l,d)
if __name__ == '__main__':
with Manager() as manager:
d = manager.dict()
l = manager.list(range(5))
p_list = []
for i in range(10):
p = Process(target=f, args=(d, l))
p.start()
p_list.append(p)
for res in p_list:
res.join()
l.append("from parent")
print(d)
print(l)还有一个：进程间共享数据
from multiprocessing import Process, Manager
import os
def f(d, l):
d[os.getpid()] =os.getpid()
l.append(os.getpid())
print(l)
if __name__ == '__main__':
with Manager() as manager:
d = manager.dict() #{} #生成一个字典，可在多个进程间共享和传递
l = manager.list(range(5))#生成一个列表，可在多个进程间共享和传递
p_list = []
for i in range(10):
p = Process(target=f, args=(d, l))
p.start()
p_list.append(p)
for res in p_list: #等待结果
res.join()
print(d)
print(l)- 进程锁 （保证屏幕打印的时候不会乱）
from multiprocessing import Process, Lock
def f(l, i):
#l.acquire()
print('hello world', i)
#l.release()
if __name__ == '__main__':
lock = Lock()
for num in range(100):
Process(target=f, args=(lock, num)).start()- 进程池
from multiprocessing import Process, Pool,freeze_support
import time
import os
def Foo(i):
time.sleep(2)
print("in process",os.getpid())
return i + 100
def Bar(arg):
print('-->exec done:', arg,os.getpid())
if __name__ == '__main__':
#freeze_support()
pool = Pool(processes=3) #允许进程池同时放入5个进程
print("主进程",os.getpid())
for i in range(10):
pool.apply_async(func=Foo, args=(i,), callback=Bar) #callback=回调
#pool.apply(func=Foo, args=(i,)) #串行
#pool.apply_async(func=Foo, args=(i,)) #串行
print('end')
pool.close()
pool.join() #进程池中进程执行完毕后再关闭，如果注释，那么程序直接关闭。.join()
扫描二维码关注公众号，回复：
3328393 查看本文章
