code2040

Tech Assessment for the CODE2040 application for Summer 2017

Step I: Registration

Code: 1resgister.py

To get started, you’re first going to connect to the registration endpoint. It lives here: http://challenge.code2040.org/api/register

The registration endpoint expects a JSON dictionary with two keys, token and github. This JSON should be sent in the body of your HTTP request.

For token, pass in a string with the token you see above. For github, pass in the URL of the repository you created in the last step.

Hint: HTTP has a few types of “methods.” The registration endpoint is going to be expecting you to use POST to send your JSON.

Step II: Reverse a string

Code: 2reverse.py

Once you’re registered, it’s time to get started on the challenges. The first one is straightforward. You’re going to reverse a string. That is, if the API says “cupcake,” you’re going to send back “ekacpuc.”

POST a JSON dictionary with the key token and your token value to this endpoint: http://challenge.code2040.org/api/reverse

This endpoint will return a string that your code should then reverse, as in the example above. Once that string is reversed, send it back to us. POST some JSON to: http://challenge.code2040.org/api/reverse/validate

Use the token for your token. Use the key string for your reversed string.

Hint: There’s more than one way to skin a cat. However you reverse the string, all that matters to the API is that it’s flipped around accurately. That said, many libraries can do this work for you with very little code. There’s no shame in doing it the easy way—if you can figure out how.

Step III: Needle in a haystack

Code: 3needle.py

Next, let’s check your skills for working with collections.

We’re going to send you a dictionary with two values and keys. The first value, needle, is a string. The second value, haystack, is an array of strings. You’re going to tell the API where the needle is in the array.

Grab that dictionary from here, again by POSTing your token: http://challenge.code2040.org/api/haystack

Locate the needle in the haystack array. You’re going to send back the position, or “index,” of the needle string. The API expects indexes to start counting at 0.

POST your results to: http://challenge.code2040.org/api/haystack/validate

Use the key token for your token. Use the key needle for the integer representing where the needle was in the array.

Hint: You’ll probably use a loop to solve this one.

Step IV: Prefix

Code: 4prefix.py

Great job -- but we’re not done with collections.

In this challenge, the API is going to give you another dictionary. The first value, prefix, is a string. The second value, array, is an array of strings. Your job is to return an array containing only the strings that do not start with that prefix.

Note: The strings in your array should be in the same order as in the original array. POST your token here: http://challenge.code2040.org/api/prefix

Once you’ve built your array, POST a dictionary here: http://challenge.code2040.org/api/prefix/validate

Use the key token for your token. Use the key array for your array.

Hint: You’ll need a little string-fu to complete this challenge. But rest assured: comparing the beginnings of strings is a common task. Your platform’s standard libraries might even have some code to help you do this.

Step V: The dating game

Code: 5datinggame.py

Great job so far. The last challenge is a little different. You’re going to work with dates and times.

The API will again give you a dictionary. The value for datestamp is a string, formatted as an ISO 8601 datestamp. The value for interval is a number of seconds.

You’re going to add the interval to the date, then return the resulting date to the API. POST your token here: http://challenge.code2040.org/api/dating

Then POST a dictionary with your results here: http://challenge.code2040.org/api/dating/validate

Use the key token for your token. Use the key datestamp for an ISO 8601 datestamp string.

Hints:

• Make sure your datestamp is formatted the same way as the one the API gives you.
• Dates are hard! Don’t feel badly if you’re scratching your head on this one. Most platforms have libraries to help with date and time tasks. Don’t be afraid of using one to solve this challenge.