Assignment Handout
Contributors: Alicia Wang, Conner Swenberg
Last updated
Contributors: Alicia Wang, Conner Swenberg
Last updated
Due Date: Wednesday 10/23, 11:59pm EST
You will be building a Reddit style community forum where people can make posts and make comments on posts.
We have provided the starting files you will need to complete this assignment for your convenience. This also simplifies your submission by just having to zip this same folder.
We have shown you how to use the Flask framework to set up routes and respond to network requests. Your assignment is to implement a series of routes following the provided specification for responding to sample requests. This assignment has 7 routes for you to implement. If you are struggling with the assignment, we recommend referring to the demo to see a concrete example.
Just like we showed in the demo, we want you to create a datastore for all posts using a Python dictionary. Your keys should be integers corresponding to post ids and values should be post dictionary objects that mimic the data shown in the API Specification.
You may also pre-populate your dictionary with data for testing purposes.
Reference the demo for specifics on defining route syntax. We recommend approaching routes in the order they appear in the API specification. After defining your route and function to return a response, open up Postman and test your route. Testing with Postman simply involves creating a new request tab, entering your server's URL, choosing a request method, and clicking the Send button.
A README.txt file is included in the starter code for you to fill out after completing the assignment. Also note that you will not receive extra credit for extra credit challenges you complete if you do not let us know for when we grade!
Common mistakes in styling are:
NOT HAVING documentation/comments in each of your routes (a one-line comment is sufficient!)
Naming variables with CamelCase instead of snake_case
Too much/too little empty spaces/empty lines
Leaving in commented code
Take some time looking through the guide to learn how to make tests using Postman. You should submit your Postman collection along with your CMS submission. The best way to get full credit for your tests is to ensure that you check that the response from your API matches what the API specification is expecting to receive. Please make sure that all your tests pass when we run your collection (make sure to clear your database before running to ensure you get the result we will get).
While that should be enough to get full credit, your tests can be cleaner and easier to change if you use variables or environments. It's up to you how much you want to learn and incorporate into your tests - the better you get at it the easier the assignments will be in the future and the likelier your API will pass the test cases we release on the first try.
If you'd prefer to learn how to use Postman through a video, here is a link to everything you'll need to know for this class; however, the audio quality is quite poor due to a technical error. If you think you would benefit from a re-recording of a Postman demo, indicate that on the feedback form and we will be happy to record one.
Next, zip the starter folder and submit on CMS. For reference, your directory structure should look like the following:
For clarification, this means that you SHOULD NOT include your virtual environment or pycache file in your final submission. Doing so will lose you a few points on the project.
To receive credit for your assignment, you must fill out the feedback form so that we can better understand how effectively we are teaching and how long students are spending on assignments.
Students will most benefit from our class time if they come in with a few things done.
+1 point
Validate body content of POST requests
You've already enforced that post bodies come in with the required fields, now make sure those fields contain valid content. We will passing in malformed inputs that violate
type preconditions
logical preconditions (e.g. invalid URL*)
We are expecting a 400 Bad Request to be thrown when validating the contents as well. To ensure that your changes do not conflict with the base test cases, please create these changes in new routes under
POST/api/extra/
Specifically, we are looking for changes in all post requests so
POST/api/extra/posts/
POST/api/extra/posts/{id}/comments/
POST/api/extra/posts/{pid}/comments/{cid}/
+1 point
Allow sorting through URL parameters
URL parameters are a way to pass data through a GET request through the request URL (just like how we pass data through a POST request by using a post body). We want you to build functionality to accept a URL parameter at the end of the /api/posts/ route (now as /api/extra/posts/) in the following form:
{WHEREVER YOUR SERVER IS HOSTED}/api/extra/posts/?key1=value1&key2=value2…
Since we want to sort the most popular posts (according to number of upvotes), you will also need to implement your own route to increment the upvote value of a post.
POST/api/extra/posts/{id}/
Make the default behavior of calling this route (making a request with no post body) be incrementing the upvotes by 1.
You will need to Google around on your own to implement this. We highly recommend trying to Google your question and find a StackOverflow post first (chances are someone has tried to do this before) and if you cannot find anything then perhaps consider the official Flask documentation (though this may be very dense to look through!). Of course, feel free to ask TAs during office hours if you are really stumped!
Please use the following naming conventions for your URL parameters:
Key: sort
Value: increasing or decreasing
So, for example, /api/extra/posts/?sort=increasing would return posts in increasing order.