Path: csiph.com!aioe.org!.POSTED!not-for-mail
From: Fabien <fabien.maussion@gmail.com>
Newsgroups: comp.lang.python
Subject: urlopen, six, and py2
Date: Wed, 2 Mar 2016 15:05:46 +0100
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Xref: csiph.com comp.lang.python:103869

Hi,

it seems that urlopen had no context manager for versions < 3. The 
following code therefore will crash on py2 but not on py3.

from six.moves.urllib.request import urlopen
with urlopen('http://www.google.com') as resp:
     _ = resp.read()

Error:
AttributeError: addinfourl instance has no attribute '__exit__'

I actually wonder if this is not something that the six library should 
take care of upstream, but in the meantime I could simply do what is 
suggested on this stackoverflow post:

http://stackoverflow.com/questions/30627937/tracebaclk-attributeerroraddinfourl-instance-has-no-attribute-exit

My question is: why does the python3 version need a "with" block while 
the python2 version doesn't? Can I skip the "with" entirely, or should I 
rather do the following:

from six.moves.urllib.request import urlopen

try:
     with urlopen('http://www.google.com') as resp:
         _ = resp.read()
except AttributeError:
     # python 2
     resp = urlopen('http://www.google.com')
     _ = resp.read()

(which is quite ugly).

Thanks!

Fabien