第一次嘗試使用current.futures建立線程-為什么我沒有輸出？

Question

我是python的新手，所以我的代碼可能存在多處錯誤。 但是我無法調試，因為我實際上沒有任何輸出，包括任何錯誤。 希望有幫助。 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))

輸出：

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

編輯：這是與此類似的問， Concurrent.futures使用指南-一個同時使用線程和處理的簡單示例 ，但是就像OP所說的那樣，答案太復雜了！

Answer 1

您正在將具有兩個值的元組映射到該函數。 在每個映射上，它只發送一個參數，但是您的函數需要兩個論點comic_start和comic_end

要看到這一點，您可以排除其他爭論並執行以下操作：

def simple_function(first_arg):
    print(first_arg)

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

結果：

1
100

修改后的代碼：

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)