python不同步

Question

想象一下20 MB的文本文件。我正在通过字符读取字符并提取有用的信息。实际上我有两个主要功能，一个是读取文件，另一个是提取信息。类似这样的：

def reader(path): 
    f = open(path, 'r') 
    source = f.read() 
    f.close() 

    while True: 
     # here is where I read char by char and call the function extractor 

def extractor(s): 
    # here I extract the useful information 

现在，我的目标是在提取器工作时继续阅读。所以基本上，我的问题是什么才能实现我的目标？

Answer 1

您可以使用生产者/消费者线程。线程可以使用Queue.Queue进行同步。

编辑：生产者/消费者系统的一个例子：

from threading import Thread 
from Queue import Queue 


def produce(queue, n_items): 
    for d in range(n_items): 
     queue.put(d) 
     print "put {0} in queue".format(d) 

def consume(queue, n_items): 
    d = 0 
    while d != n_items -1: # You need some sort of stop condition 
     d = queue.get() 
     print "got {0} from queue".format(d) 

def start_producer_and_consumer(wait): 
    q = Queue() 
    consumer_thread = Thread(target = consume, args = (q, 10)) 
    producer_thread = Thread(target = produce, args = (q, 10)) 
    producer_thread.start() 
    consumer_thread.start() 
    if wait: 
     producer_thread.join() 
     consumer_thread.join() 

if __name__ == '__main__': 
    start_producer_and_consumer(True) 

至于如果执行此，你会看到，一切都会以正确的顺序被消耗。