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Episode #300: A Jupyter merge driver for git

Published Tue, Sep 6, 2022, recorded Tue, Sep 6, 2022.

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About the show

Sponsored by Microsoft for Startups Founders Hub.

Special guest: Seth Larson

Brian #1: Test your packages and wheels

  • I’ve been building some wheels the last couple of weeks with various tools:
    • flit, flit-core, and flit build
    • hatch, hatchling, and hatch build
    • setuptools, build_meta, and python -m build
  • There are a few projects I’ve used to make sure my projects are in good shape
    • wheel-inspect - you can inspect within Python code through inspect_wheel() function that converts to json. Or use on the command line with wheel2json
    • check-wheel-contents - a linter for wheels
    • tox - easily test the building, installation, and running of a package locally
      • I actually start here, then utilize the other two tools
  • Should have been obvious, but it wasn’t to me
    • Projects saved on git (such as gitHub) don’t keep wheels in git. (this was obvious)
    • When installing from git using pip install git+https://path/to/git/repo.git
      • Your local pip will run the packaging backend to build the wheel before installing.
      • Yet another way to test packaging.

Michael #2: The Jupyter+git problem is now solved

  • Jupyter notebooks don’t work with git by default (they inherently have meaningless conflicts).
  • With nbdev2, the Jupyter+git problem has been totally solved.
  • Uses a set of hooks which provide clean git diffs, solve most git conflicts automatically, and ensure that any remaining conflicts can be resolved entirely within the standard Jupyter notebook environment.
  • The techniques used to make the merge driver work are quite fascinating

Seth #3: Help us test system trust stores in Python

  • Package aiming to replace certifi called “truststore”, use system trust stores for HTTPS instead of a static list of certificates.
  • Problem truststore is solving usually manifests in corporate networks: “unable to get local issuer certificate”.
  • Experimental support added to pip to prove the implementation
  • Users can try out the functionality and report issues.

Brian #4: Making plots in your terminal with plotext

  • Bob Belderbos
  • Tutorial on using plotext - that’s one t in the middle
  • With the rise of CLI usage, plots are a nice addition.
  • Bob’s plot is great, but check out the options in the plotext docs
    • lots-o-plots
    • streaming data
    • images
    • subplots
  • so fun

Michael #5: jinja2-fragments

Seth #6: SLSA 3 Generic Builder for GitHub Actions GA

  • Supply chain Levels for Software Artifacts, or SLSA (“salsa”)
  • Tools to attest to and verify “provenance” of artifacts, ie “where it came from”
  • Prove cryptographically that artifacts are built from a specific GitHub repository, commit, tag. Another future defense against stolen PyPI credentials/accounts.
  • Generic builder means you can sign anything, like wheels/sdists



  • Bring your pytest books to PyBay, if you want them signed.
    • I’m only bringing a small amount.
  • I’ll be presenting
    • "Sharing is Caring - pytest fixture edition” at 3:05
    • “Experts Panel on Testing in Python” at 7:00
  • And be a zombie on my 8 am flight back unless I can change my reservation.
  • That’s this weekend, Sat Sept 10, in SF



Joke: Dev just after work

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