Module 5

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In Module 6, you will learn about python, a scripting language, and Django, a web framework.

This article contains your assignments for Module 6.

Individual Assignments

Python Tutorial

Install Python Tools

• sudo yum install python-setuptools
  
• sudo yum install python-devel

Python Assignment

• You will write a python script that reads a set of student grades in from a file and does some basic parsing and processing. here is the section of the python tutorial on reading and writing files.
• An example grades file is here. For the sake of simplicity you can assume that the file name is always going to be grades.txt.
• The first line of the file is of the form: NUM_LABS,NUM_EXAMS,LAB_WEIGHT
• All of the other lines in the file are of the form: FIRSTNAME LASTNAME|GRADE|TYPE
• The FIRSTNAME and LASTNAME fields are the student's full name (always only a first and last name), the GRADE is one grade for the student, and the TYPE describes what kind of assignment the grade was for, in this case either a 'lab' or an 'exam'.
• Your script should read in a grades file with the above format and perform the following:
  1. Compute the final grade for every student, given that there were a total of NUM_LABS labs, NUM_EXAMS exams, and that the labs account for a total of LAB_WEIGHT percent of the grade.
  2. Compute the final letter grade based on the final numeric grade (A = 90 or above, B = 80 - 90, C = 70 - 80, D = 60 - 70, F = below 60). 
  3. Ignore any blank lines.
  4. Sort the students by last name, and print out final grades in that sorted order.
  5. No names should be hard coded into the script (you will run your script on another file with different student names when we grade your assignment).
  6. Finally, the script should take one optional command line argument, which is a string to match against student names.  Only names that match the string in full or in part, should be printed out with their final grades.
     • For example, with the argument 'John' grades for both John Smith and John Locke should be printed (if those are the only two Johns in the grades.txt file)

Django Tutorial

Install Djgano

This procedure assumes you are using and Amazon AMI Linux on an ec2 instance. An in-depth install guide can be found on the Django website, but a quick version is below. Run these commands as root.

• Install Distribute (prerequisite for pip):
curl http://python-distribute.org/distribute_setup.py | python
• Install pip:
curl https://raw.github.com/pypa/pip/master/contrib/get-pip.py | python

• Install Django using pip:

pip install Django

That's it.

Django Assignment

Complete the tutorial on the django website. You will create a Polls app. There are four parts to this tutorial.

It is important you do all the steps in the tutorial to get comfortable defining models, views, templates, and using the interactive shell and the admin app. Understanding the concepts will make the project go much quicker.

• Part 1

  • Create a project
  • Start the development server
  • Setup an SQLite database
  • Create the Polls app and define the models
  • Interact with the database using the interactive python shell

• Part 2

  • Activate the admin site
  • Add the poll app to the admin site
  • Modify the database using the admin site

• Part 3

  • Configure URL handling
  • Create some views

• Part 4

  • Write a form that modifies the database
  • Refactor to use generic views

  Switch to Apache Webserver

  • run yum install mod_wsgi to install the apache and the module necessary for serving your django app.
  • Add these lines to /etc/httpd/conf/httpd.conf

    <Alias /static /var/www/*APPNAME*/static
    <Directory /var/www/*APPNAME*/static>
    Order deny,allow
    Allow from all
    </Directory>
    WSGIScriptAlias / /var/www/*APPNAME*/apache/django.wsgi
    

  • Move your app to /var/www and make the directory /var/www/*APPNAME*/apache. In that directory create the file django.wsgi and Inside that file put:

    import os
    import sys
    sys.path.append('/var/www/*APPNAME*')
    os.environ['DJANGO_SETTINGS_MODULE'] = '*APPNAME*.settings'
    import django.core.handlers.wsgi
    application = django.core.handlers.wsgi.WSGIHandler()
    

• Be sure to change any references to old paths in the django settings.py file

Group Project

You may work in pairs on this project. Your group will create a new project using one of the options below.

Image Tagging/Browsing Site

A site that lets users upload images, apply multiple tags to them, and browse through images of a certain tag. When looking at an image, it lists all associated tags so you can switch albums.

Requirements

• Make a database that stores images and tags. An image can have multiple tags, and each tag can have multiple images.
• The home page should allow users to find tags that they want to view. (e.g. lolcat).
• After clicking a link to a tag, it should take you to a page with the newest image for that tag.
• Clicking on the current image should take to to the next image according to date added. When at the last image, link to the first.
• Make it clear which tag you are currently browsing. Beside or below the current image, also display the full list of tags that belong to the current image (e.g. lolcat, meme, internet, funny). You should be able to click on any of the tags to begin looking through that collection of images.
• Provide a way for users who are logged in to add new images and new tags.
• Validate user input
• Provide a way for users to register, login, and change their password.
• Have a link that sends an email to a user with a link for resetting their password in case they forget it.
• Style the site with statically-served CSS (i.e. link to static .css files and don't write CSS inside the html templates)

Notes

• You may store images as external web links.
• Try to find and figure out as many Django shortcuts as you can. You do not need to write your own url parsing, validation, login/registration/reset forms etc. For these common tasks, there is almost always built-in functionality that will do what you want in very few lines.
• The admin interface and the interactive python shell will be very helpful when getting started with the database.

Grading

Due Date: Wednesday December 5th by 1pm (both individual and group)

Python Assignment	Points
Compute Final Grades	0.25
Compute Letter Grade	0.25
Sort by Last Name	0.25
Accept Command Line Argument	0.25
Django Assignment:
Models defined, database set up	0.25
Admin app enabled and working	0.25
urls matched to correct views	0.25
Templates for viewing and voting using generic views	0.25
Apache serving the site	0.25
Group Portion:
Models defined and database set up	2
View of single image with current tag and list of all tags	2
Navigation between images and tags	2
Main page displays all tags sorted by number of images	2
User registration, login/logout and change password	2
Forgot password sends email with working reset link	2
Validation of all user input	2
Add new images and tags, only if logged in	2
Static CSS applied to some templates	2
Creative Portion	2

Total Points = 29