Harvard CS 50x — Week 9 (Flask)

(This is a summary of week 9 from the Harvard CS 50x series. Visit this page to see more from this series! )

It’s currently a Friday night in London, and I’m feeling a little exhausted. Really looking forward to the holidays now!

However, before I distract myself by dreaming too much of the upcoming holidays, I’m spending my Friday night catching up on the second last video of CS50x. This week’s focus was Flash.


  • Flask → A web app framework mainly used for Python
  • Design Pattern (Ways that humans write code)
  • MVC (Model, View, Controller)
  • Flask has certain organisational recommendations
Example of an organisational recommendation in Flask
  • “flask run” → starts flask app
  • GET → request.args
  • POST → request.form
  • Reusability of code
  • Layouts + use of Jinja
  • Froshims
  • Error checking
  • flask_mail
  • Sessions
Example of sessions represented by a “stamp on the hand”
  • Cookies
  • Logging in / out
  • JavaScript
  • “%” → wildcard for SQL commands
  • JSON(JavaScript Object Notation) → jsonify (takes a python list and returns it in a JSON format)
  • jQuery
  • AJAX


This week was really straightforward for me as the principals covered have already been explained to my previously during my Bootcamp course with Flatiron School. Nonetheless, it was intriguing to see everything written in Python using Flask. Can’t believe I only have 1 week of CS50x left - then I’ll be done :)!

Links to Assignments

No assignment this week.



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