Making PyPI's test suite 81% faster (via) Fantastic collection of tips from Alexis Challande on speeding up a Python CI workflow.
I've used pytest-xdist to run tests in parallel (across multiple cores) before, but the following tips were new to me:
COVERAGE_CORE=sysmon pytest --cov=myproject
tells coverage.py on Python 3.12 and higher to use the new sys.monitoring mechanism, which knocked their test execution time down from 58s to 27s.- Setting
testpaths = ["tests/"]
inpytest.ini
letspytest
skip scanning other folders when trying to find tests. python -X importtime ...
shows a trace of exactly how long every package took to import. I could have done with this last week when I was trying to debug slow LLM startup time which turned out to be caused be heavy imports.
Recent articles
- Two publishers and three authors fail to understand what "vibe coding" means - 1st May 2025
- Understanding the recent criticism of the Chatbot Arena - 30th April 2025
- Qwen 3 offers a case study in how to effectively release a model - 29th April 2025