Description
This issue describes how to implement the itertools
Module concept exercise for the Python track.
The related concept documents issue can be found here.
✅ Getting started
If you have not yet created or contributed to a concept exercise, this issue will require some upfront reading to give you the needed background knowledge. Some good example exercises to look at in the repo:
💡Example Exercises💡 (click to expand)
We also recommend completing one or more of the concept exercises (they're called "learning exercises") on the website.
Please please read the docs before starting.
Posting PRs without reading these docs will be a lot more frustrating for you during the review cycle, and exhaust Exercism's maintainers' time. So, before diving into the implementation, please go through the following documents:
General Contributing Docs:
- Contributing to Exercism | Exercism and GitHub | - Contributor Pull Request Guide
- What are those Weird Task Tags about?
- Exercism Formatting and Style Guide
- Exercism Markdown Specification
- Reputation
Documents on Language Tracks and Concept Exercises
- Building Language Tracks: An Overview
- What are Concept Exercises?
- Concept Exercise Specifications
- Concept Exercise Stories
🎯 Goal
The goal of the concept exercise described in this issue is to teach understanding/use of the itertools
module in Python.
💡Learning objectives
Learn more about iteration
tools the Python Standard Library provides through the itertools
module.
Build and understanding of and use the following functions from the module, as well as practicing some of the recipes included :
- At least one of the infinite itertators
count()
,cycle()
,, orrepeat()
accumulate()
product()
chain()
&chain.from_iterable()
groupby()
islice()
zip_longest()
and thezip() built-in
permutations()
combinations()
🤔 Concepts
iteration
iterators
itertools
🚫 Topics that are Out of scope
Concepts & Subjects that are Out of Scope (click to expand)
classes
&class customization
beyond the use of theitertools
methods.class-inheritance
beyond what is needed to customizeiteration
usingitertools
comprehensions
beyond what is needed to work withitertools
comprehensions
inlambdas
coroutines
decorators
beyond what is needed to work withitertools
functions
andhigher-order functions
beyond what might be needed to work withitertools
functools
and relatedmap()
,filter()
andfunctools.reduce()
(they have their own exercise which is a prerequisite to this one)generators
beyond what might be needed to work withitertools
(they have their own exercise which is a prerequisite to this one)lambdas
beyond what might be needed to work withitertools
- using an
assignment expression
or "walrus" operator (:=
) - class decorators
enums
↩️ Prerequisites
These are the concepts/concept exercises the student should be familiar with before taking on/learning this concept.
Exercise Prerequisites (click to expand)
basics
booleans
comparisons
rich-comparisons
dicts
dict-methods
functions
functional tools
generators
higher-order functions
- Identity methods
is
andis not
iteration
lists
list-methods
loops
numbers
sequences
sets
strings
string-methods
tuples
📚 Resources for Writing and Reference
Resources (click to expand)
Exercise Ideas & Stories
Should you need inspiration for an exercise story, you can find a collection here. You can also port an exercise from another track, but please make sure to only to include tasks that actually make sense in Python and that add value for a student. Remove/replace/add tasks as needed to make the concept clear/workable.
📁 Exercise Files to Be Created
File Detail for this Exercise
|
♾️ Exercise Metadata - Track
For more information on concept exercises and formatting for the Python track config.json
, please see config.json
. The track config.json
file can be found in the root of the Python repo.
You can use the below for the exercise UUID. You can also generate a new one via exercism configlet, uuidgenerator.net, or any other favorite method. The UUID must be a valid V4 UUID.
- Exercise UUID :
c4620b29-0db0-4541-8cfe-7048fab27f7f
- concepts should be filled in from the Concepts section in this issue
- prerequisites should be filled in from the Prerequisites section in this issue
🎶 Implementation Notes
-
As a reminder, code in the
.meta/examplar.py
file should only use syntax & concepts introduced in this exercise or one of its prerequisite exercises. We run all ourexamplar.py
files through PyLint, but do not strictly require module docstrings. We do require function docstrings similar to PEP257. See this concept exerciseexemplar.py
for an example. -
Please do not use comprehensions, generator expressions, or other syntax not previously covered either in the introduction to this exercise, or to one of its prerequisites. Please also follow PEP8 guidelines.
-
In General, tests should be written using
unittest.TestCase
and the test file should be named<EXERCISE-NAME>_test.py
.- All asserts should contain a "user friendly" failure message (these will display on the webiste to students, so be as clear as you can).
- We use a
PyTest custom mark
to link test cases to exercise task numbers. - We also use
unittest.subtest
to parameterize test input where/when needed.
Here is an example testfile that shows all three of these in action.
-
While we do use PyTest as our test runner and for some implementation tests, please check with a maintainer before using a PyTest-specific test method, fixture, or feature.
-
Our markdown and JSON files are checked against prettier . We recommend setting prettier up locally and running it prior to submitting your PR to avoid any CI errors.
🆘 Next Steps & Getting Help
If you'd like to work on this issue, comment saying "I'd like to work on this"
(there is no real need to wait for a response, just go ahead, we'll assign you and put a[claimed]
label on the issue).- If you have any questions while implementing, please post the questions as comments in here, or contact one of the maintainers on our Slack channel.