python 3 compatibility

[dirk-thomas]

@tfoote @wjwwood Please review.

[wjwwood]

Does this overlap at all with #43?

[dirk-thomas]

I was not aware of the other pull request. The other one seems to contain more things (some of which I am not sure why they are necessaru) but outdated. This pull request contains the changes I had to make to get the rosdep command init and update working with Python 3.3 on Saucy.

[tfoote]

I think this should be cPickle. It provided a noteable speedup. I'm not sure if that still holds for python3.

[dirk-thomas]

I updated the pull request to try import cPickle as pickle which was the initial idea of it.

[tfoote]

One comment otherwise +1

[wjwwood]

In Python3 c... prefixed things are gone, the fastest implementation is always made available. But I think your comment holds that cPickle should probably be used for Py2.x cases.

[tfoote]

Python 3 unit tests failing. Looks like rosdistro needs to be ported first.

Writing /tmp/easy_install-cnt65i/rosdistro-0.2.15/setup.cfg
Running rosdistro-0.2.15/setup.py -q bdist_egg --dist-dir /tmp/easy_install-cnt65i/rosdistro-0.2.15/egg-dist-tmp-3rikdi
  File "build/bdist.linux-x86_64/egg/rosdistro/rosdistro.py", line 372
    except Exception, ex:
                    ^
SyntaxError: invalid syntax
zip_safe flag not set; analyzing archive contents...
  File "/home/travis/virtualenv/python3.2/lib/python3.2/site-packages/rosdistro-0.2.15-py3.2.egg/rosdistro/rosdistro.py", line 372
    except Exception, ex:
                    ^
SyntaxError: invalid syntax

[dirk-thomas]

It's finally green. Please (re)review.

[tfoote]

+1

[wjwwood]

Does this work the same on Py26?

[dirk-thomas]

Should work. The optional argument should be the limit - never the exception itself. I guess 2.x was just nicer in handling this wrong argument.

[wjwwood]

+1