Get Errno from Python Requests ConnectionError?

I had troubles getting the same results with python 3.6 and requests 2.18. I managed to get the errno using the http and socket modules :

import socket, html
try:
    http.client.HTTPConnection('invalid').connect()
except (socket.gaierror, ConnectionError) as e:
    print(e.errno)

Hopefully it helps someonelse.

I think you can access it using e.args[0].reason.errno.

This is probably documented somewhere, but usually when I have to track down something like this I just try it at the console and dig around a little bit. (I use IPython so it's easy to do tab-inspection, but let's try it without).

First, let's generate an error using

import requests
try:
    requests.get("http://not.a.real.url/really_not")
except requests.exceptions.ConnectionError as e:
    pass

which should give us the error in e:

>>> e
ConnectionError(MaxRetryError("HTTPConnectionPool(host='not.a.real.url', port=80): Max retries exceeded with url: /really_not (Caused by <class 'socket.gaierror'>: [Errno -2] Name or service not known)",),)

Information is usually in args:

>>> e.args
(MaxRetryError("HTTPConnectionPool(host='not.a.real.url', port=80): Max retries exceeded with url: /really_not (Caused by <class 'socket.gaierror'>: [Errno -2] Name or service not known)",),)
>>> e.args[0]
MaxRetryError("HTTPConnectionPool(host='not.a.real.url', port=80): Max retries exceeded with url: /really_not (Caused by <class 'socket.gaierror'>: [Errno -2] Name or service not known)",)

Looking inside, we see:

>>> dir(e.args[0])
['__class__', '__delattr__', '__dict__', '__doc__', '__format__', '__getattribute__',
 '__getitem__', '__getslice__', '__hash__', '__init__', '__module__', '__new__',
 '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setstate__', '__sizeof__',
 '__str__', '__subclasshook__', '__unicode__', '__weakref__', 'args', 'message', 'pool',
 'reason', 'url']

reason looks encouraging:

>>> e.args[0].reason
gaierror(-2, 'Name or service not known')
>>> dir(e.args[0].reason)
['__class__', '__delattr__', '__dict__', '__doc__', '__format__', '__getattribute__',
 '__getitem__', '__getslice__', '__hash__', '__init__', '__module__', '__new__',
 '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setstate__', '__sizeof__',
 '__str__', '__subclasshook__', '__unicode__', '__weakref__', 'args', 'errno', 'filename',
 'message', 'strerror']
>>> e.args[0].reason.errno
-2