The Test Framework

Install Python

This class will be using Python 3. If you don’t have Python 3 installed, please visit the official Python downloads page and click the yellow “Download Python 3.8.2” button.

If you have any problems installing, please ask for help.

Download The Exercises

Throughout this workshop we’ll be using a test framework to check your code. Here’s what you need to know to make it all work.

Download exercise test files. When unzipped, it should create a new folder called exercises. It contains the test framework we will be using, so you will be working from this folder.

This file you downloaded (, when unzipped, should create a new folder called exercises. It contains the test framework we will be using, so you will be working from this folder. It also contains the files you will need to modify for most of the exercises in the class.

Confirm the Framework is Working

Change directory to your exercises directory, and run the following:

$ python is_ok

If successful, you’ll receive this message:

Testing is_ok

Congrats and welcome to the Test Framework!
The message confirms the Test Framework is working! Yay!
Pat yourself on the back for successful installation!\n
Continue reading this section of the course instructions. \n
We will get started in a moment.
Ran 1 test in 0.000s


To see what tests exist, you can also enter python on the command line (or python3 or py -3 by itself: You should see a list of lots of tests:

Please select a thing to test


first: Return the first item in given iterable.
is_iterator: Return ``True`` if given iterable is an iterator.


around: Yield a tuple of the previous, current, and next items.
deep_flatten: Flatten an iterable of iterables.
pairwise: Yield a tuple containing each item and the item following it.
stop_on: Yield from the iterable until the given value is reached.
unique: Yield iterable elements in order, skipping duplicate values.

Where to Write Your Code

At the beginning of each exercise you’ll see a note describing where to find it. The exercises will be functions you’ll write or modify in the existing .py files in the exercises directory. It’s important that you write your code in the right place, or the tests won’t work.

How to Run the Tests

Once you’ve written your code and you’re ready to test it, we will use Python to run followed the name of the exercise in your command prompt. Always type these commands from the exercises directory. The test framework knows where to find the files you tell it to test.

How you run this at the terminal will depend on your operating system and which version(s) of Python you have installed.

If you only have one version of Python installed, and it is Python 3, you can run the tests (for example) for the get_vowel_names exercise in like this:

Linux/Mac terminal:

$ python get_vowel_names

Windows command window:

> py get_vowel_names

If you have more than one version of Python installed, you’ll need to specify Python 3 like this:

Linux/Mac terminal:

$ python3 get_vowel_names

Windows command window:

> py -3 get_vowel_names

In all cases you should see a FAILED message at the end of the output, like this:

Ran 3 tests in 0.000s

FAILED (errors=3)

Your tests should be failing at first because you haven’t written any code to get them to pass yet!

Passing the Tests

Once you’ve attempted the exercise by adding code to the get_vowel_names function in, if your code has passed the tests, you’ll see some variation of this message:

Testing get_vowel_names

Ran 3 tests in 0.002s

Write more Pythonic code

I send out 1 Python exercise every week through a Python skill-building service called Python Morsels.

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