Python exception for HTTP response codes

Question

I'd like to raise a Python-standard exception when an HTTP response code from querying an API is not 200, but what specific exception should I use? For now I raise an OSError:

if response.status_code != 200:
  raise OSError("Response " + str(response.status_code)
                  + ": " + response.content)

I'm aware of the documentation for built-in exceptions.

Answer 1

You can simply call Response.raise_for_status() on your response:

>>> import requests
>>> url = 'http://stackoverflow.com/doesnt-exist'
>>> r = requests.get(url)
>>>
>>> print r.status_code
404
>>> r.raise_for_status()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "requests/models.py", line 831, in raise_for_status
    raise HTTPError(http_error_msg, response=self)
requests.exceptions.HTTPError: 404 Client Error: Not Found

This will raise a requests.HTTPError for any 4xx or 5xx response.

See the docs on Response Status Code for a more complete example.

---

Note that this does not exactly do what you asked (status != 200): It will not raise an exception for 201 Created or 204 No Content, or any of the 3xx redirects - but this is most likely the behavior you want: requests will just follow the redirects, and the other 2xx are usually just fine if you're dealing with an API.