为什么保存的文件显示 None 而控制台显示正确的响应？

Question

当我尝试将响应保存到文件时，实际响应并未保存，即使它显示在控制台中也是如此。保存在文件中的结果是None。请参阅下面的示例

from concurrent.futures import ThreadPoolExecutor
import requests
#from timer import timer


#########  create test file

URLsTest = '''
https://en.wikipedia.org/wiki/NBA
https://en.wikipedia.org/wiki/NFL
'''.strip()

with open('input.txt', 'w') as f:
    f.write(URLsTest)
    
####################

with open('input.txt', 'r') as f:
    urls=f.read().split('\n')    # url list

def fetch(tt):  # received tuple
    session, url = tt
    print('Processing')
    with session.get(url) as response:
        print(response.text)

#@timer(1, 5)
def main():
    with ThreadPoolExecutor(max_workers=100) as executor:
        with requests.Session() as session:  # for now, just one session
            results = executor.map(fetch, [(session, u) for u in urls])  # tuple list (session, url), each tuple passed to function
            executor.shutdown(wait=True)
    # write all results to text file
    with open('output.txt', 'w') as f2:
        for r in results:  # tuple (url, html)
            f2.write("%s\n" % r)
            
main()

响应文件 - output.txt

None    
None

Answer 1

首先，您可以避免打印 html，因为您正在将该输出保存到文件中。这样你就可以避免使用资源来打印结果。

那么，您的提取不会 return 为 results 获取任何内容。因此，您应该将 print 更改为 return 所以不是打印 return 而是 response.text

# print(response.text)
return response.text

Answer 2

理想的做法是不打印 html，因为您必须将工作或输出保存到一个文件，这样您就无法以原始形状打印整个结果。

为什么保存的文件显示 None 而控制台显示正确的响应？

Why is the file saved showing None while console shows the correct response?

python

text

python-requests

output

concurrent.futures