删除.com python之后的所有内容

Question

我在站点urls.tmp文件中使用了3个urls获得了这个文件：

https://site1.com.br/wp-content/uploads/2020/06/?SD
https://site2.com.br/wp-content/uploads/tp-datademo/home-4/data/tp-hotel-booking/?SD
https://site3.com.br/wp-content/uploads/revslider/hotel-home/?MD

我想删除每个"com.br/“之后的所有内容。

我试过这段代码：

# open the file
sys.stdout = open("urls.tmp", "w")

# start remove
for i in "urls.tmp":
    url_parts = urllib.parse.urlparse(i)
    result = '{uri.scheme}://{uri.netloc}/'.format(uri=url_parts)
    print(result) #overwrite the file

# close the file
sys.stdout.close()

但是输出给了我一个奇怪的东西：

:///
:///
:///
:///
:///
:///
:///
:///

我是初学者，我做错什么了？

Answer 1

您正在迭代"urls.tmp"字符串本身，但希望逐行遍历打开的文件对象。

所以，试一试吧：

with open("urls.tmp", "r") as urls_file:
    for line in urls_file:
        url_parts = urllib.parse.urlparse(line)
        result = "{uri.scheme}://{uri.netloc}/".format(uri=url_parts)
        print(result)

编辑:作者更新了最初的问题，提到源文件内容应该用处理过的urls重写，下面是示例：

new_urls = []

with open("urls.tmp", "r") as urls_file:
    old_urls = urls_file.readlines()

for line in old_urls:
    url_parts = urllib.parse.urlparse(line)
    proc_url = "{uri.scheme}://{uri.netloc}/\n".format(uri=url_parts)
    new_urls.append(proc_url)

with open("urls.tmp", "w") as urls_file:
    urls_file.writelines(new_urls)

Answer 2

请参阅Savva Surenkov答案来解决您的问题。

您可以使用字符串的拆分方法，例如：

url = r"https://site1.com.br/wp-content/uploads/2020/06/?SD"

split_by = "com.br/"

new_url = url.split(split_by)[0] + split_by
# this gives you the part before <split_by> and then we can attach it again
new_url == r"https://site1.com.br"

如果您想要添加一些额外的检查，您可以查看正则表达式。

那些你没有要求的东西，但作为初学者可能会帮助你。我建议使用

with open("urls.tmp", "w") as f:
   # do something with f

或

import pathlib

urls = pathlib.Path("urls.tmp").read_text()
# which gives you all lines in single string

在平原open上空。如果您想了解更多这方面的信息，我建议您查看上下文管理器。

还有从Python3.6开始的f-strings，在我看来，它们比"{}".format更容易阅读。

Answer 3

您可以继续使用string的find()方法。

urllist=[
'https://site1.com.br/wp-content/uploads/2020/06/?SD',
'https://site2.com.br/wp-content/uploads/tp-datademo/home-4/data/tp-hotel-booking/?SD',
'https://site3.com.br/wp-content/uploads/revslider/hotel-home/?MD']

newlist=[]
breaktext='com.br/'
for item in urllist:
    position=item.find(breaktext)
    newlist.append(item[:position+len(breaktext)])

print (newlist)