Bug#571443: Support using "in" operator to test whether a package is in the cache

[Julian Andres Klode <jak@debian.org>]

Am Donnerstag, den 25.02.2010, 06:53 -0800 schrieb Matt Kraai:
> Package: python-apt
> Version: 0.7.93.1
> Severity: wishlist
> 
> Hi,
> 
> I'm using python-apt's apt_pkg.Cache class to determine which packages
> are installed.  I have to use a try...except statement to check
> whether a package is in the cache first, though, since using the "in"
> operator to do so generates an exception:
> 
>  Python 2.5.5 (r255:77872, Feb  1 2010, 19:53:42) 
>  [GCC 4.4.3] on linux2
>  Type "help", "copyright", "credits" or "license" for more information.
>  >>> import apt_pkg
>  >>> apt_pkg.init()
>  >>> cache = apt_pkg.Cache()
>  Reading package lists... Done
>  Building dependency tree       
>  Reading state information... Done
>  >>> 'foo' in cache
>  Traceback (most recent call last):
>    File "<stdin>", line 1, in <module>
>  TypeError: argument of type 'apt_pkg.Cache' is not iterable
>  >>> 
> 
> I wish that this worked.
Use::

    'foo' in cache.packages

I could also try to implement most of the mapping stuff in
apt_pkg.Cache, so one can just treat the cache as a mapping.

-- 
Julian Andres Klode  - Debian Developer, Ubuntu Member

See http://wiki.debian.org/JulianAndresKlode and http://jak-linux.org/.