多线程的使用场景 & 多进程用法

· IO操作不占CPU，计算占用CPU
· python多线程不适合CPU密集型（1+1）操作的任务，适合IO（socketserver）密集型的任务。
代码范例1：简单的进程实现

import threading,multiprocessing, time
def test():
    print(threading.get_ident())
def fun(name):
    time.sleep(1)
    print("hello,",name)
    t = threading.Thread(target=test)
    t.start()
if __name__ == '__main__':
    p = multiprocessing.Process(target=fun,args=('fone',))
    p.start()
    p.join()

# 注意：进程使用与线程类似，但实例化之前一定要加上if __name__ == '__main__':

代码范例2：

from multiprocessing import Process
import os
def info(title):
    print(title)
    print('module name:', __name__)
    print('parent process:', os.getppid())
    print('process id:', os.getpid())
    print("\n")
def f(name):
    info('\033[31;1mfrom 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()

# 输出：
main process line
module name: __main__
parent process: 6660
process id: 7772

from child process function f
module name: __mp_main__
parent process: 7772
process id: 7648

hello bob