TDD with flit

Episode 81 · July 17th, 2019 · 25 mins 20 secs

About this Episode

In the last episode, we talked about going from script to supported package.
I worked on a project called subark and did the packaging with flit.

Today's episode is a continuation where we add new features to a supported package and how to develop and test a flit based package.


  • viewing stages of a project with git tags
  • flit support for editable installs
  • flit description entry in pyproject.toml to put README on pypi.
  • development dependencies in pyproject.toml
  • editor layout for optimal TDD-ing
  • test case grouping
  • modifications to traditional TDD that helps me develop faster.

code and command snippets from episode:

For git checkout of versions:

$ git clone
$ cd submark
$ python3 -m venv venv --prompt submark
$ source ./bin/activate
(submark) $ git checkout v0.1
... etc ...
(submark) $ git checkout v0.7

To grab the latest again:

(submark) $ git checkout master

pyproject.toml change for README to show up on pypi:

description-file = ""

Adding dev dependencies to pyproject.toml:

test = ["pytest", "pytest-cov", "tox"]

Installing in editable mode (in top level repo directory). works in mac, linux, windows:

(submark) $ flit install --pth-file

or for mac/linux:

(submark) $ flit install -s

Support Test & Code : Python Testing for Software Engineering

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