python多进程编程实例_Python编程：multiprocessing多进程（代码实例）

获取进程id

import multiprocessing

import os

def foo():

print(__name__)

print("parent:", os.getppid())

print("current:", os.getpid())

if __name__ &＃61;&＃61; "__main__":

foo() # 主进程调用

p &＃61; multiprocessing.Process(target&＃61;foo)

p.start() # 新开进程调用

"""

__main__

parent: 952

current: 188

__mp_main__

parent: 188

current: 6492

"""

多进程测试

import multiprocessing

import time, threading

from pycharm_fontcolor import Colors, FontColor

def func(i):

print(FontColor.set_color("线程号:{}".format(threading.get_ident()), Colors.green), i)

def foo(i):

print(FontColor.set_color("进程:", Colors.red), i)

t &＃61; threading.Thread(target&＃61;func, args&＃61;(i,)) # 进程中新开线程

t.start()

if __name__ &＃61;&＃61; "__main__":

start_time &＃61; time.time()

for i in range(5):

p &＃61; multiprocessing.Process(target&＃61;foo, args&＃61;(i,))

p.start()

end_time &＃61; time.time()

print(FontColor.set_color("时间:", Colors.blue), end_time - start_time)

"""

时间: 0.05303597450256348

进程: 0

线程号:8968 0

进程: 1

线程号:7620 1

进程: 2

进程: 3

线程号:9204 2

线程号:2492 3

进程: 4

线程号:6512 4

"""

进程池

from multiprocessing import Pool

import time, os

def foo(i):

time.sleep(2)

print("process:", i, os.getpid())

return i &＃43; 1 # 参数将传递给回调函数

def bar(i): # 做回调函数&＃xff0c;由主进程执行

print("bar", i, os.getpid())

if __name__ &＃61;&＃61; "__main__":

print(os.getpid())

pool &＃61; Pool(processes&＃61;3) # 允许同时放入3个进程

for i in range(10):

# p &＃61; pool.apply(func&＃61;foo, args&＃61;(i,)) # 串行

p &＃61; pool.apply_async(func&＃61;foo, args&＃61;(i,), callback&＃61;bar) # 并行

print("done")

pool.close() # 先关闭入口

pool.join() # 在等待执行

"""

8120

done

process: 0 5452

bar 1 8120

process: 1 8360

bar 2 8120

process: 2 7908

bar 3 8120

process: 3 5452

bar 4 8120

process: 4 8360

bar 5 8120

process: 5 7908

bar 6 8120

process: 6 5452

bar 7 8120

process: 7 8360

bar 8 8120

process: 8 7908

bar 9 8120

process: 9 5452

bar 10 8120

"""

进程队列

from multiprocessing import Process, Queue

def foo(q):

q.put("你好")

if __name__ &＃61;&＃61; "__main__":

q &＃61; Queue() # 进程队列

p &＃61; Process(target&＃61;foo, args&＃61;(q,))

# p &＃61; Thread(target&＃61;foo, args&＃61;(q,))

p.start()

print(q.get()) # 你好

进程管道

from multiprocessing import Process, Pipe

def foo(conn):

conn.send("hello")

conn.close()

if __name__ &＃61;&＃61; "__main__":

parent_conn, child_conn &＃61; Pipe() # 管道传送数据

p &＃61; Process(target&＃61;foo, args&＃61;(child_conn,))

p.start()

print(parent_conn.recv()) # hello

多进程实现数据共享

from multiprocessing import Process, Manager

import os

def foo(dct, lst):

dct[os.getpid()] &＃61; os.getpid()

lst.append(os.getpid())

print(os.getpid())

if __name__ &＃61;&＃61; "__main__":

manager &＃61; Manager() # 实现进程间共享数据

dct &＃61; manager.dict()

lst &＃61; manager.list()

processes &＃61; []

for i in range(5):

p &＃61; Process(target&＃61;foo, args&＃61;(dct, lst))

p.start()

processes.append(p)

for process in processes: # 等待结果

process.join()

print(dct)

print(lst)

"""

3816 5376 7500 8332 1124

{3816: 3816, 5376: 5376, 8332: 8332, 7500: 7500, 1124: 1124}

[3816, 5376, 7500, 8332, 1124]

"""

进程锁

from multiprocessing import Lock, Process

def foo(lock, i):

lock.acquire()

print("hello world!", i)

lock.release()

if __name__ &＃61;&＃61; "__main__": # 主动执行会继续下面的内容&＃xff0c;被当做模块调用则不会

lock &＃61; Lock() # 实例化进程锁

for i in range(5):

p &＃61; Process(target&＃61;foo, args&＃61;(lock, i))

p.start()

"""

hello world! 2

hello world! 1

hello world! 0

hello world! 3

hello world! 4

"""