第一次尝试使用current.futures建立线程-为什么我没有输出？

Question

我是python的新手，所以我的代码可能存在多处错误。 但是我无法调试，因为我实际上没有任何输出，包括任何错误。 希望有帮助。 我在python 3.5中。 干杯!

print('starting')
def simple_function(comic_start, comic_end):  
    for urlNumber in range(comic_start, comic_end):
        print('Downloading page http://xkcd.com/%s...' % (urlNumber))       
        driver = selenium.webdriver.PhantomJS()
        driver.get('http://xkcd.com/%s' % (urlNumber))
        print('finding page')
        form= driver.title
        print(driver.title)   
    driver.quit()
with concurrent.futures.ThreadPoolExecutor(max_workers=10) as executor:
    executor.map(simple_function, (1, 100))

输出：

runfile('/Users/Seansmac/Desktop/Python/my_classroom/threading_training/concurrent.f1.py', wdir='/Users/Seansmac/Desktop/Python')
starting

编辑：这是与此类似的问， Concurrent.futures使用指南-一个同时使用线程和处理的简单示例 ，但是就像OP所说的那样，答案太复杂了！

Answer 1

您正在将具有两个值的元组映射到该函数。 在每个映射上，它只发送一个参数，但是您的函数需要两个论点comic_start和comic_end

要看到这一点，您可以排除其他争论并执行以下操作：

def simple_function(first_arg):
    print(first_arg)

with cf.ThreadPoolExecutor(max_workers=10) as executor:
     executor.map(simple_function, (1, 100))

结果：

1
100

修改后的代码：

import concurrent.futures as cf

def simple_function(_range):

    #fill with driver stuff etc
    for num in _range:
        print('Downloading page http://xkcd.com/%s...' % (num))       

_max = 200 #max range you want
workers = 10
with cf.ThreadPoolExecutor(max_workers=workers) as e:

    cs= _max // workers #chunksize to split across threads

    #we chunk the range to be split across the threads so you can iterate
    #over the chunked range in the mapped function.

    #x + cs if x + cs <= _max else _max next upper bound by chunksize but 
    #we don't want to exceed the maximum range you want, so we default to _max
    #if the next upper bound exceeds this

    #x - 1 if x!= 0 else x, start initial range at 0, and last upper
    #bound is exclusive so x - 1 if were not at the initial range.
    ranges = [range(x - 1 if x != 0 else x, x + cs if x + cs <= _max else _max) 
              for x in range(0, _max, cs)]

    e.map(simple_function, ranges)