Discovering the package of an open window

[Michael Spencer]

What is the best way to discover the package a program is in by clicking
on an open window?

So far I've been using xprop to get the PID of the window, reading where
/proc/<PID>/exe points too, and then running apt-file search on that.

However, for some programs, like LibreOffice Writer, I get
libreoffice-core, not libreoffice-writer.

For the program I'm writing, Contributor Console (written in python),
the executable is /usr/bin/python2.7, even though I launched it with the
command contributor-console.

So, what is the best way to accurately discover the package a program is
in by clicking on an open window?

Thank you,

-- 
Michael Spencer

If thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.
- Romans 10:9

Whatsoever ye do in word or deed, do all in the name of the Lord Jesus, giving thanks to God and the Father by him.
- Colossians 3:17