According to the title that.

Solution like this one:
apt-cache rdepends packagename

Does list all the reverse package. Although most of the packages in the list I do not have in my system installed. Example:

apt-cache rdepends python-gpgme

python-gpgme



Reverse Depends:

  python-bzrlib

  bzr

  python-gpgme:i386

  nautilus-dropbox

  assword

  alot

  python-gpgme-dbg

  python-bzrlib

  bzr

I do not have bzr, nautilus, alot, and others installed.

So, what is the correct command to find out the list of installed dependent package to that "target" package?

I need to know if python-gpgme is OKAY to purge.