Processes and threads.py

from multiprocessing import Process
import os

# def run_proc(name):
#     print('Run child process %s (%s)...' % (name, os.getpid()))

# if __name__=='__main__':
#     print('Parent process %s.' % os.getpid())
#     p = Process(target=run_proc, args=('test',))
#     print('Child process will start.')
#     p.start()
#     p.join()
#     print('Child process end')


# from multiprocessing import Pool
# import os, time, random
#
# def long_time_task(name):
#     print('Run task %s (%s)...' % (name, os.getpid()))
#     start = time.time()
#     time.sleep(random.random() * 3)
#     end = time.time()
#     print('Task %s runs %0.2f seconds.' % (name, (end - start)))
#
# if __name__=='__main__':
#    print('Parent process %s.' % os.getpid())
#    p = Pool(4)
#    for i in range(5):
#         p.apply_async(long_time_task, args=(i,))
#     print('Waiting for all subprocesses done...')
#     p.close()
#     p.join()
#     print('All subprocesses done.')


import subprocess

print('$ nslookup www.python.org')
r = subprocess.call(['nslookup', 'www.python.org'])
print('Exit code:', r)

# print('$ nslookup')
# p = subprocess.Popen(['nslookup'], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
# output, err = p.communicate(b'set q=mx\npython.org\nexit\n')
# print(output.decode('utf-8'))
# print('Exit code:', p.returncode)

from multiprocessing import Process, Queue
import os, time, random

# 写数据进程执行的代码
def write(q):
    print('Process to write: %s' % os.getpid())
    for value in ['A','B', 'C']:
        print('Put %s to queue...' % value)
        q.put(value)
        time.sleep(random.random())


# 读数据进程执行的代码:
def read(q):
    print('Process to read: %s' % os.getpid())
    while True:
        value = q.get(True)
        print('Get %s from queue.' % value)

if __name__=='__main__':

    # 父进程创建Queue，并传给各个子进程
    q = Queue()
    pw = Process(target=write, args=(q,))
    pr = Process(target=read, args=(q,))

    # 启动子进程pw，写入:
    pw.start()

    # 启动子进程pr，读取:
    pr.start()

    # 等待pw结束:
    pw.join()

    # pr进程里是死循环，无法等待其结束，只能强行终止:
    pr.terminate()


import time, threading

# 新线程执行的代码:

def loop():
    print('threat %s is running...' % threading.current_thread().name)
    n = 0
    while n < 5:
        n = n + 1
        print('threat %s >>> %s' % (threading.current_thread().name, n))
        time.sleep(1)
    print('threat %s ended.' % threading.current_thread().name)

print('threat %s is running...' % threading.current_thread().name)
t = threading.Thread(target=loop, name='LoopThread')
t.start()
t.join()
print('threat %s ended.' % threading.current_thread().name)