Python请求库异常处理

Question

我正在使用 python 请求库(参见 here)创建下载服务，以从另一台服务器下载数据。问题是有时我会收到 503 错误，我需要显示相应的消息。请参阅下面的示例代码:

import requests
s = requests.Session()
response = s.get('http://mycustomserver.org/download')

我可以从 response.status_code 检查并获得 status code = 200。 但是我如何针对特定错误try/catch，在这种情况下，我希望能够检测到503 错误 并适本地处理它们。

我该怎么做？

Answer 1

为什么不做

class MyException(Exception);
   def __init__(self, error_code, error_msg):
       self.error_code = error_code
       self.error_msg = error_msg

import requests
s = requests.Session()
response = s.get('http://mycustomserver.org/download')

if response.status_code == 503:
    raise MyException(503, "503 error code")

编辑:

似乎请求库也会使用 response.raise_for_status() 为您引发异常

>>> import requests
>>> requests.get('https://google.com/admin')
<Response [404]>
>>> response = requests.get('https://google.com/admin')
>>> response.raise_for_status()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/requests/models.py", line 638, in raise_for_status
    raise http_error
requests.exceptions.HTTPError: 404 Client Error: Not Found

编辑2:

用下面的 try/except 包裹你 raise_for_status

try:
    if response.status_code == 503:
        response.raise_for_status()
except requests.exceptions.HTTPError as e: 
    if e.response.status_code == 503:
        #handle your 503 specific error