我发现这非常有用：创建与内核一样多的线程，并让它们执行（大量）任务（在本例中，调用shell程序）：

import Queue
import threading
import multiprocessing
import subprocess

q = Queue.Queue()
for i in range(30): # Put 30 tasks in the queue
    q.put(i)

def worker():
    while True:
        item = q.get()
        # Execute a task: call a shell program and wait until it completes
        subprocess.call("echo " + str(item), shell=True)
        q.task_done()

cpus = multiprocessing.cpu_count() # Detect number of cores
print("Creating %d threads" % cpus)
for i in range(cpus):
     t = threading.Thread(target=worker)
     t.daemon = True
     t.start()

q.join() # Block until all tasks are done

使用全新的concurrent.futures模块

def sqr(val):
    import time
    time.sleep(0.1)
    return val * val

def process_result(result):
    print(result)

def process_these_asap(tasks):
    import concurrent.futures

    with concurrent.futures.ProcessPoolExecutor() as executor:
        futures = []
        for task in tasks:
            futures.append(executor.submit(sqr, task))

        for future in concurrent.futures.as_completed(futures):
            process_result(future.result())
        # Or instead of all this just do:
        # results = executor.map(sqr, tasks)
        # list(map(process_result, results))

def main():
    tasks = list(range(10))
    print('Processing {} tasks'.format(len(tasks)))
    process_these_asap(tasks)
    print('Done')
    return 0

if __name__ == '__main__':
    import sys
    sys.exit(main())

执行器方法对于所有以前接触过Java的人来说似乎都很熟悉。

还有一个附带说明：为了保持宇宙的正常，如果你不使用上下文，不要忘记关闭你的池/执行器（这是如此棒，它为你做了）

这很容易理解。这里有两种简单的线程处理方法。

import time
from concurrent.futures import ThreadPoolExecutor, as_completed
import threading

def a(a=1, b=2):
    print(a)
    time.sleep(5)
    print(b)
    return a+b

def b(**kwargs):
    if "a" in kwargs:
        print("am b")
    else:
        print("nothing")
        
to_do=[]
executor = ThreadPoolExecutor(max_workers=4)
ex1=executor.submit(a)
to_do.append(ex1)
ex2=executor.submit(b, **{"a":1})
to_do.append(ex2)

for future in as_completed(to_do):
    print("Future {} and Future Return is {}\n".format(future, future.result()))

print("threading")

to_do=[]
to_do.append(threading.Thread(target=a))
to_do.append(threading.Thread(target=b, kwargs={"a":1}))

for threads in to_do:
    threads.start()
    
for threads in to_do:
    threads.join()

只需注意：线程不需要队列。

这是我可以想象的最简单的例子，它显示了10个并发运行的进程。

import threading
from random import randint
from time import sleep


def print_number(number):

    # Sleeps a random 1 to 10 seconds
    rand_int_var = randint(1, 10)
    sleep(rand_int_var)
    print "Thread " + str(number) + " slept for " + str(rand_int_var) + " seconds"

thread_list = []

for i in range(1, 10):

    # Instantiates the thread
    # (i) does not make a sequence, so (i,)
    t = threading.Thread(target=print_number, args=(i,))
    # Sticks the thread in a list so that it remains accessible
    thread_list.append(t)

# Starts threads
for thread in thread_list:
    thread.start()

# This blocks the calling thread until the thread whose join() method is called is terminated.
# From http://docs.python.org/2/library/threading.html#thread-objects
for thread in thread_list:
    thread.join()

# Demonstrates that the main process waited for threads to complete
print "Done"

这里是多线程，有一个简单的例子会很有帮助。您可以运行它并轻松了解多线程在Python中的工作方式。我使用了一个锁来防止访问其他线程，直到前面的线程完成它们的工作。通过使用这行代码，

t锁定=线程。有界信号量（值=4）

您可以一次允许多个进程，并保留将在稍后或完成之前的进程后运行的其余线程。

import threading
import time

#tLock = threading.Lock()
tLock = threading.BoundedSemaphore(value=4)
def timer(name, delay, repeat):
    print  "\r\nTimer: ", name, " Started"
    tLock.acquire()
    print "\r\n", name, " has the acquired the lock"
    while repeat > 0:
        time.sleep(delay)
        print "\r\n", name, ": ", str(time.ctime(time.time()))
        repeat -= 1

    print "\r\n", name, " is releaseing the lock"
    tLock.release()
    print "\r\nTimer: ", name, " Completed"

def Main():
    t1 = threading.Thread(target=timer, args=("Timer1", 2, 5))
    t2 = threading.Thread(target=timer, args=("Timer2", 3, 5))
    t3 = threading.Thread(target=timer, args=("Timer3", 4, 5))
    t4 = threading.Thread(target=timer, args=("Timer4", 5, 5))
    t5 = threading.Thread(target=timer, args=("Timer5", 0.1, 5))

    t1.start()
    t2.start()
    t3.start()
    t4.start()
    t5.start()

    print "\r\nMain Complete"

if __name__ == "__main__":
    Main()

使用线程/多处理的最简单方法是使用更多高级库，如autothread。

import autothread
from time import sleep as heavyworkload

@autothread.multithreaded() # <-- This is all you need to add
def example(x: int, y: int):
    heavyworkload(1)
    return x*y

现在，您可以为函数提供int列表。Autothread将为您处理所有事务，并只提供并行计算的结果。

result = example([1, 2, 3, 4, 5], 10)