Glossary

What is a Taskfile

Like Makefile, but tasks are written in bash: link. Basically, it allows you to define custom, arbitrarily complex tasks, and then run then with task <taskname>.

What is uv

A super fast python package manager that everyone’s been talking about. Just go check it out.

For me the primary usage for uv is replacing pip install ... with uv pip install ... – just makes things run faster (and with more clear error messages). However, here I’ll talk about a new feature called uv run – it allows you to run an arbitrary command without leaving current environment.

Taskfile example: MDAnalysis

Basically, the Taskfile:

version: '3'

tasks:
  clean:
    cmds:
      - rm -rf .venv
  ipython:
    cmds:
      - ipython
  build:
    cmds:
      - echo 'running build...'
      - uv venv -p 3.12
  rebuild:
    cmds:
      - task: clean
      - task: build
  install:
    cmds:
      - task: build
      - uv pip install -e './package[extra_formats,analysis,doc,parallel]' 
      - uv pip install -e './testsuite' pytest-xdist pytest-testmon pytest-random-order
      - uv pip install ipython ipykernel
  test:
    cmds:
      - task: build
      - task: install
      - uv run python -m pytest --random-order -n $(nproc --ignore=4) {{.CLI_ARGS}}
  check:
    cmds:
      - uv run python -m pytest --random-order --testmon -n $(nproc --ignore=4) {{.CLI_ARGS}}
  all:
    cmds:
      - task: clean
      - task: build
      - task: install
      - task: test

It allows you to build the full environment quickly (~2 minutes with cold cache), install the things I always install for tests but keep forgetting when re-installing the package (pytest-xdist and pytest-random-order), and run either all tests (task test) or only those that could’ve changed correctness since the last time I ran pytest (task check). The last one is useful when developing code.

Also, I can run ipython console, making sure that I’m running inside current environment, with task ipython. Pretty neat!

Don’t forget to add this Taskfile to your .git/info/exclude file in order not to commit it by accident.