Python 2 and 3 are separate beasts. If you install a script into the site-packages of one version, you are not installing it into the other.

I'd install it through pip, but you'll need the right version of pip.

sudo apt-get install python3-pip

sudo pip-3.3 install pylint

This will replace your 2.7 version. We can confirm this by checking less $(which pylint):

#!/usr/bin/python3.3

# EASY-INSTALL-ENTRY-SCRIPT: 'pylint==1.0.0','console_scripts','pylint'

__requires__ = 'pylint==1.0.0'

import sys

from pkg_resources import load_entry_point



if __name__ == '__main__':

    sys.exit(

        load_entry_point('pylint==1.0.0', 'console_scripts', 'pylint')()

    )