find the install path of some software in linux (ubuntu)

find the install path of some software
    like python:    

dpkg -L python

    or the start path:

which python
/usr/bin/python

    or find all the dir and file use 'locate'

warrior@warrior:~$ locate python | more -10
/etc/python
/etc/python2.7
/etc/python3
/etc/python3.4
/etc/apparmor.d/abstractions/python
/etc/python/debian_config
/etc/python2.7/sitecustomize.py
/etc/python3/debian_config
/etc/python3.4/sitecustomize.py
/home/warrior/.python-eggs
--More--

    or want to display some system environment variable

warrior@warrior:~$ echo $PATH
/usr/local/sbin:/usr/local/bin: