请求库在 Python 2 和 Python 3 上崩溃

Question

我正在尝试使用以下代码解析带有 requests 和 BeautifulSoup 库的任意网页：

try:
    response = requests.get(url)
except Exception as error:
    return False

if response.encoding == None:
    soup = bs4.BeautifulSoup(response.text) # This is line 809
else:
    soup = bs4.BeautifulSoup(response.text, from_encoding=response.encoding)

在大多数网页上都可以正常工作。但是，在某些任意页面 (

Traceback (most recent call last):
  File "/home/dotancohen/code/parser.py", line 155, in has_css
    soup = bs4.BeautifulSoup(response.text)
  File "/usr/lib/python3/dist-packages/requests/models.py", line 809, in text
    content = str(self.content, encoding, errors='replace')
  TypeError: str() argument 2 must be str, not None

供参考，这是requests库的相关方法：

@property
def text(self):
    """Content of the response, in unicode.

    if Response.encoding is None and chardet module is available, encoding
    will be guessed.
    """

    # Try charset from content-type
    content = None
    encoding = self.encoding

    # Fallback to auto-detected encoding.
    if self.encoding is None:
        if chardet is not None:
            encoding = chardet.detect(self.content)['encoding']

    # Decode unicode from given encoding.
    try:
        content = str(self.content, encoding, errors='replace') # This is line 809
    except LookupError:
        # A LookupError is raised if the encoding was not found which could
        # indicate a misspelling or similar mistake.
        #
        # So we try blindly encoding.
        content = str(self.content, errors='replace')

    return content

可以看出，当抛出此错误时，我没有传入编码。 我如何不正确地使用该库，我可以做些什么来防止这个错误？这是在 Python 3.2.3 上，但我也可以在 Python 2 上得到相同的结果。

Answer 1

这意味着服务器没有发送标题中内容的编码，chardet 库也无法确定内容的编码。实际上，您故意测试是否缺少编码；如果没有可用的编码，为什么要尝试获取解码的文本？

您可以尝试将解码留给BeautifulSoup 解析器：

if response.encoding is None:
   soup = bs4.BeautifulSoup(response.content)

并且没有需要将编码传递给BeautifulSoup，因为如果.text没有失败，那么您使用的是Unicode，并且BeautifulSoup无论如何都会忽略编码参数：

else:
   soup = bs4.BeautifulSoup(response.text)