在python中创建线程

Question

我有一个脚本,我想要一个功能与另一个同时运行.

我看过的示例代码:

import threading

def MyThread (threading.thread):
    # doing something........

def MyThread2 (threading.thread):
    # doing something........

MyThread().start()
MyThread2().start()

我无法正常工作.我宁愿使用线程函数而不是类来实现.

谢谢你的帮助.

这是工作脚本,感谢您的帮助.

from threading import Thread

class myClass():

    def help(self):
        os.system('./ssh.py')

    def nope(self):
        a = [1,2,3,4,5,6,67,78]
        for i in a:
            print i
            sleep(1)


if __name__ == "__main__":
    Yep = myClass()
    thread = Thread(target = Yep.help)
    thread2 = Thread(target = Yep.nope)
    thread.start()
    thread2.start()
    thread.join()
    print 'Finished'

Answer 1

您不需要使用子类Thread来完成这项工作 - 看看我在下面发布的简单示例,看看如何:

from threading import Thread
from time import sleep

def threaded_function(arg):
    for i in range(arg):
        print("running")
        sleep(1)


if __name__ == "__main__":
    thread = Thread(target = threaded_function, args = (10, ))
    thread.start()
    thread.join()
    print("thread finished...exiting")

这里我展示了如何使用线程模块创建一个调用普通函数作为其目标的线程.你可以看到我如何在线程构造函数中传递我需要的任何参数.

Answer 2

您的代码存在一些问题:

def MyThread ( threading.thread ):

• 你不能用函数子类化; 只有一堂课
• 如果您打算使用子类,则需要threading.Thread,而不是threading.thread

如果你真的只想用函数做这个,你有两个选择:

使用线程:

import threading
def MyThread1():
    pass
def MyThread2():
    pass

t1 = threading.Thread(target=MyThread1, args=[])
t2 = threading.Thread(target=MyThread2, args=[])
t1.start()
t2.start()

有线程:

import thread
def MyThread1():
    pass
def MyThread2():
    pass

thread.start_new_thread(MyThread1, ())
thread.start_new_thread(MyThread2, ())

doc for thread.start_new_thread

Answer 3

我试图添加另一个join(),它似乎工作.这是代码

from threading import Thread
from time import sleep

def function01(arg,name):
for i in range(arg):
    print(name,'i---->',i,'\n')
    print (name,"arg---->",arg,'\n')
    sleep(1)


def test01():
    thread1 = Thread(target = function01, args = (10,'thread1', ))
    thread1.start()
    thread2 = Thread(target = function01, args = (10,'thread2', ))
    thread2.start()
    thread1.join()
    thread2.join()
    print ("thread finished...exiting")



test01()

Answer 4

Python 3 具有启动并行任务的功能。这使我们的工作更加轻松。

它用于线程池和进程池。

下面给出一个见解：

ThreadPoolExecutor 示例

import concurrent.futures
import urllib.request

URLS = ['http://www.foxnews.com/',
        'http://www.cnn.com/',
        'http://europe.wsj.com/',
        'http://www.bbc.co.uk/',
        'http://some-made-up-domain.com/']

# Retrieve a single page and report the URL and contents
def load_url(url, timeout):
    with urllib.request.urlopen(url, timeout=timeout) as conn:
        return conn.read()

# We can use a with statement to ensure threads are cleaned up promptly
with concurrent.futures.ThreadPoolExecutor(max_workers=5) as executor:
    # Start the load operations and mark each future with its URL
    future_to_url = {executor.submit(load_url, url, 60): url for url in URLS}
    for future in concurrent.futures.as_completed(future_to_url):
        url = future_to_url[future]
        try:
            data = future.result()
        except Exception as exc:
            print('%r generated an exception: %s' % (url, exc))
        else:
            print('%r page is %d bytes' % (url, len(data)))

另一个例子

import concurrent.futures
import math

PRIMES = [
    112272535095293,
    112582705942171,
    112272535095293,
    115280095190773,
    115797848077099,
    1099726899285419]

def is_prime(n):
    if n % 2 == 0:
        return False

    sqrt_n = int(math.floor(math.sqrt(n)))
    for i in range(3, sqrt_n + 1, 2):
        if n % i == 0:
            return False
    return True

def main():
    with concurrent.futures.ThreadPoolExecutor(max_workers=5) as executor:
        for number, prime in zip(PRIMES, executor.map(is_prime, PRIMES)):
            print('%d is prime: %s' % (number, prime))

if __name__ == '__main__':
    main()

Answer 5

使用实现多线程进程的简单方法threading

相同的代码片段

import threading

#function which takes some time to process 
def say(i):
    time.sleep(1)
    print(i)

threads = []
for i in range(10):
    
    thread = threading.Thread(target=say, args=(i,))

    thread.start()
    threads.append(thread)

#wait for all threads to complete before main program exits 
for thread in threads:
    thread.join()