python-learning/1104.py at master · miaozaiye/python-learning · GitHub

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#print ('Process (%s) start...' %os.getpid())
#pid = os.fork()
#if pid == 0:
#	print ('I am child process (%s) and my parent is %s.' %(os.getpid(),os.getppid()))
#else:
#	print ('I(%s) just created a child process (%s).' %(os.getpid(),pid))

from multiprocessing import Process,Pool


# 子进程要执行的代码
#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() #设置当前时间戳
#    time.sleep(random.random() * 3) # 模拟程序执行 由random.random()生成的随机浮点数时间*3
#    end = time.time() #获取当前结束的时间
#    print('Task %s runs %0.2f seconds.' % (name, (end - start))) #该任务执行了的时间，去小数点后2位

#if __name__=='__main__':
#    print('Parent process %s.' % os.getpid())
#    p = Pool(5)
#    for i in range(5):
#        p.apply_async(long_time_task, args=(i,)) #把进程数0，1，2，3，4 分别传入函数
#    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)


#import subprocess

#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 subprocess

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)