Packaging python script to Debian follows strict instructions, using the following instructions, most of the steps can be skipped hence making it easy and fast.
If you like video go to https://www.youtube.com/watch?v=a9GzDZB5VeU. This video doesn't show setup.py file creating which is required, but excluding that portion everything is same as below.

Lets convert this mymood.py into deb package.

import time
def analyze():
    try:
        print '\nHello! I am Dr.Psycho, your mood analyzer:)'
        print 'Answer me:'
        time.sleep(2)
        answer_list = []
        def validate_ans(ans):
           try:
               ans = int(ans)
               print ans
               if ans not in [1, 2]:
                   print 'Enter 1 or 2\n'
                   return None
               elif ans == 1:
                   return ans
               elif ans == 2:
                   return 0
           except Exception:
               print 'Enter 1 or 2\n'
               return None
        print '\nHow many questions can you answer?'
        print '1. More than 20\n2. Less than 10'
        ans = raw_input()
        while True:
            ans = validate_ans(ans)
            if ans != None:
                break
            ans = raw_input()
        answer_list.append(ans)
        print '\nYou are the worst thing ever existed?'
        print '1. Nope\n2. Kind of'
        ans = raw_input()
        while True:
            ans = validate_ans(ans)
            if ans != None:
                break
            ans = raw_input()
        answer_list.append(ans)
        print '\nAre you searching for meaning of life?'
        print '1. I dont\n2. Yes, I will find it some day'
        ans = raw_input()
        while True:
            ans = validate_ans(ans)
            if ans != None:
                break
            ans = raw_input()
        answer_list.append(ans)
        print '\nLast question. Do you feel happy if everyone died except you?'
        print '1. Not at all \n2. Oh yes'
        ans = raw_input()
        while True:
            ans = validate_ans(ans)
            if ans != None:
                break
            ans = raw_input()
        answer_list.append(ans)
        print '\nHow does this yet another question feel?'
        print '1. smiling\n2. *******\n'
        ans = raw_input()
        while True:
            ans = validate_ans(ans)
            if ans != None:
                break
            ans = raw_input()
        answer_list.append(ans)
        score = sum(answer_list)
        if score == 0:
            mood_status = 'You are totally messed up, Better consult psychiatrist'
        elif score == 1:
            mood_status = 'Very frustrated'
        elif score == 3:
            mood_status = 'Bored and depressed'
        elif score in [3, 4]:
            mood_status = 'Normal'
        elif score == 5:
            mood_status = 'Enlightened'
        print '\nDr. Psycho thanks for your patience. \nYour mood: %s' % mood_status
    except KeyboardInterrupt:
        print '\nBye :('

Project Structure:

mymood

 debian

changelog

    compat

    control

    rules

    copyright

  mymood

    __init__.py

    mymood.py

    command_line.py

  README.md

  setup.py

Don't create the above structure, it will be created as you go through below steps.

1. Creating mymood and its sub directories:

$mkdir mymood

$cd mymood

$mkdir debian

$mkdir mymood

2. Setting up mymood/mymood directory:

Goto mymood/mymood directory and paste mymood.py script as shown in project structure.

Within mymood/mymood create __init__.py

$touch __init__.py

Within mymood/mymood directory create command_line.py. setup.py needs this to run script from bash just by typing mymood.

$vim command_line.py

copy the following into command_line.py

from mymood import analyze

def main():

        analyze()

3. Python's setup.py file creation:

Create a setup.py file in mymood directory as shown in project structure above.

The below code is simple and minimal setup.py for mymood, copy and change as you require.

from setuptools import setup
setup(name='mymood',
  version='0.1',
  description='your mood analyzer',
  author='mp',
  author_email='hello@micropyramid.com',
  license='MIT',
  packages=['mymood'],
  entry_points = {
    'console_scripts': ['mymood=mymood.command_line:main'],
    },
  zip_safe=False)

Console scripts is used to run the script from terminal. So from bash you can just type mymood and run the script.

4. Setting up debian directory

$mkdir debian

Devscripts package is needed to create changelog file.

$cd debian 

$sudo apt-get install devscripts

$dch --create

Now edit the file as follows:

mymood (1.0) UNRELEASED; urgency=medium

* Initial release. (Closes: #XXXXXX)

-- druuu <druuu@gmail.com>  Wed, 10 Feb 2016 15:33:03 +0530

5. Create copyright, compat, control and rules files in debian directory.

$touch compat

$touch copyright

$touch control

$touch rules

the control file looks like:

Source: mymood

Section: python

Priority: optional

Maintainer: druuu, <druuu@gmail.com>

Build-Depends: debhelper (>= 7),

Standards-Version: 3.9.2

Package: mymood

Architecture: all

Section: python

Depends: python, ${misc:Depends}, ${python:Depends}

Description: simple mood checker

mymood is a simple mood checker.

It analyze the mood by simple questions.

So this file lists dependencies, package description. The description is of two types, short and long.

Short is "simple mood checker' and the long 'mymood is a simple mood checker. It analyze the mood by simple questions'.

In the long description it should not exceed 80 characters per line.

The rules file:

#!/usr/bin/make -f
%:
  dh $@ --with python2

Note that you have python2 or python3 based on your script, dont just put python.

Also not that you use tab before dh, not spaces

The other files can be left empty.

6. Finally lets create a deb package.

Goto mymood top level direcotry and build package.

mymood     <-- you should be inside this directory

  debian

    changelog

    compat

    control

    rules
    copyright

  mymood

    __init__.py

    mymood.py

    command_line.py

  README.md

  setup.py

$fakeroot dpkg-buildpackage -b

This should create the following structure:

mymood_1.0_all.deb      <--success! we got deb package

mymood_1.0_amd64.changes

mymood

  build

  debian

    tmp

      DEBIAN

        etc..

      usr

        etc..

    changelog

    compat

    control

    rules

    copyright

    debhelper.log

    files

    substvars

  mymood

    __init__.py

    mymood.py

    command_line.py

  mymood.egg-info

  README.md

  setup.py

As you can see we get mymood_1.0_all.deb package wich can be installed by "ubuntu software center".

Ubuntu Software Center is recomended as it automatically installs dependencies

or

simply

$sudo dpkg -i mymood_1.0_all.deb     <-- this command throws errors if dependencies not satisfied. Use ubuntu softare center.

Video for the above fosshelp blog post: https://www.youtube.com/watch?v=a9GzDZB5VeU.