To set up test-driven development (TDD) with Python, pytest, and Vim: 1. Install pytest and pytest-xdist using pip. Create a "tests" folder and name test files with "test_" prefix. 2. In Vim, open files by project directory and use :vsplit to view code and tests side-by-side in split windows. Ctrl-wx swaps windows. 3. Run pytest from the project root with -f -v to watch for changes and rerun tests automatically on save.

1. TDD with python, pytest and
vim
Setting up

2. Getting Started
• pip install pytest
• pip install pytest-xdist
• If you are using Anaconda, pytest should already be installed

3. Directory/Folder structure
Create a tests folder in your
project directory
Test data for testing
dataframes
Name corresponding test files
with a test_ infront

4. Using VIM
• Open vim <filename> in the root directory
• Enter :vsplit <tests/filename> in vim’s console
• You will get a split window.
• Ctrl-wx to swap columns in the order of preference. I.e. code on left,
test on right or vice versa
• Ctrl-ww to switch editing columns

5. Using VIM - vsplit
CODE TESTS

6. Using VIM – vsplit
Cursor
Here shows
where you are
editing
code testsCtrl-ww

7. Pytest
• Run pytest -f -v in
the root of your
project directory
• Pytest will be
watching for any
changes in the code
or tests.
• Once you save
either file, it will re-
run all tests
automatically