在 python 中使用 urllib 时双引号和单引号字符串之间的不同行为

Question

我是 python 的新手，我了解到单引号和双引号字符串之间没有区别。但是我发现了一些不同的行为。

from bs4 import BeautifulSoup
import urllib.request

url1 = "http://www.backpackers.com.tw/forum/forumdisplay.php?f=310"
url2 = 'http://www.backpackers.com.tw/forum/forumdisplay.php?f=310'

如果我运行:

response = urllib.request.urlopen(url1)

结果：脚本完成且没有错误

如果我运行:

response = urllib.request.urlopen(url2)

结果：错误

C:\Users\user1\Desktop\scrape>python backpacker_tw.py
Traceback (most recent call last):
  File "C:\Python34\lib\urllib\request.py", line 1189, in do_open
    h.request(req.get_method(), req.selector, req.data, headers)
  File "C:\Python34\lib\http\client.py", line 1090, in request
    self._send_request(method, url, body, headers)
  File "C:\Python34\lib\http\client.py", line 1128, in _send_request
    self.endheaders(body)
  File "C:\Python34\lib\http\client.py", line 1086, in endheaders
    self._send_output(message_body)
  File "C:\Python34\lib\http\client.py", line 924, in _send_output
    self.send(msg)
  File "C:\Python34\lib\http\client.py", line 859, in send
    self.connect()
  File "C:\Python34\lib\http\client.py", line 836, in connect
    self.timeout, self.source_address)
  File "C:\Python34\lib\socket.py", line 509, in create_connection
    raise err
  File "C:\Python34\lib\socket.py", line 500, in create_connection
    sock.connect(sa)
ConnectionRefusedError: [WinError 10061] No connection could be made because the
 target machine actively refused it

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "backpacker_tw.py", line 7, in <module>
    response = urllib.request.urlopen(url2)
  File "C:\Python34\lib\urllib\request.py", line 153, in urlopen
    return opener.open(url, data, timeout)
  File "C:\Python34\lib\urllib\request.py", line 455, in open
    response = self._open(req, data)
  File "C:\Python34\lib\urllib\request.py", line 473, in _open
    '_open', req)
  File "C:\Python34\lib\urllib\request.py", line 433, in _call_chain
    result = func(*args)
  File "C:\Python34\lib\urllib\request.py", line 1215, in http_open
    return self.do_open(http.client.HTTPConnection, req)
  File "C:\Python34\lib\urllib\request.py", line 1192, in do_open
    raise URLError(err)
urllib.error.URLError: <urlopen error [WinError 10061] No connection could be ma
de because the target machine actively refused it>

这是错误还是我遗漏了什么？

C:\Users\user1\Desktop\scrape>python -V
Python 3.4.1

Answer 1

到文档！ PEP 8，几乎所有关于 python 代码格式的事情都结束了，声明 "In Python, single-quoted strings and double-quoted strings are the same." 这是 Python 的创建者写的，我会相信他的话为了它。

查看您的堆栈跟踪，我看到了错误 No connection could be ma de because the target machine actively refused it，所以这可能意味着当时服务器发生了一些奇怪的事情？

在 python 中使用 urllib 时双引号和单引号字符串之间的不同行为

Different behaviour between double quoted and single quoted string when using urllib in python

python

urllib

beautifulsoup

python-3.4