Comment 5 for bug 1157900

The problem manifests itself in Python 2, not Python 3:

In Python3 we get:

vagrant@quantal64:/vagrant$ python3
Python 3.2.3 (default, Oct 19 2012, 19:53:16)
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import softwareproperties.ppa
>>>

In Python 2 we get:

vagrant@quantal64:/vagrant$ python
Python 2.7.3 (default, Sep 26 2012, 21:51:14)
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import softwareproperties.ppa
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/dist-packages/softwareproperties/ppa.py", line 39, in <module>
    import pycurl
ImportError: No module named pycurl
>>>

After installing python-pycurl, the system works again:

vagrant@quantal64:/vagrant$ python
Python 2.7.3 (default, Sep 26 2012, 21:51:14)
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import softwareproperties.ppa
>>>

So yes, python-software-properties is missing a python-pycurl dependency except, perhaps, on ubuntu releases that make python3 the default python, in which case it's missing a python-pycurl "Recommends".