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Episode #219: HTMX: Dynamic and live HTML without JavaScript

Published Wed, Feb 3, 2021, recorded Wed, Feb 3, 2021.

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Special guest: Jennifer Stark - @_JAStark & guest on talkpython.fm/259

Brian #1: Do you really need a virtualenv?

  • Frost Ming doesn’t think so, based on the article You don't really need a virtualenv
  • The link slug is “introducing-pdm”, which I think would be a better title, but the first did work to get people to talk about it. Also, “Try PEP 582 today” may have been appropriate.
  • Teaching new people is a problem:
    • Telling them to first type python -m venv venv
    • Then type source venv/bin/activate or . venv/bin/activate
    • Unless you’re on windows, then type venv\scripts\activate.bat
    • Then type pip install -r requirements.txt
    • Yeah. It’s not pretty, not fun, and good luck not having anyone ask questions about why this is necessary.
  • Also the Python version is specified in the venv. So if you upgrade Python versions, what happens to existing venvs?
  • The article also discusses levels of venvs, and global tools that maybe you want not tied to each venv. But we have pipx for that, so I don’t think that’s a real issue.
  • Enter PEP 582, still in draft mode.
    • Instead of a venv directory, your project has a __pypackage__ directory. If you python -m pip install in your project directory, stuff just goes there instead of to the global Python.
    • So it kinda acts like a venv for local packages, it just doesn’t include local copies of the Python executables, and such.
    • This is probably a horrible description of 582, but oh well. Something like that.
  • pdm supports 582 today
    • PDM stands for Python Development Master
    • “It installs and manages packages in a similar way to npm that doesn't need to create a virtualenv at all!”
    • Has a workflow that reminds me of Poetry, but doesn’t use a venv, uses a package directory instead.
  • Conclusion:
    • Huge props to Frost for this. It’s cool to see a tool that supports 582 and glimpse a possible Python future.
    • However, this doesn’t solve the “teaching Python” problem. The setup is more complex than venv.
    • I’m personally sticking with venv, well virtualenv, until (and if) 582 is supported by Python and pip.

Michael #2: Copier - like cookiecutter

  • A library for rendering project templates.
  • Works with local paths and git URLs.
  • Your project can include any file and Copier can dynamically replace values in any kind of text file.
  • It generates a beautiful output and takes care of not overwrite existing files unless instructed to do so.
  • To use as a CLI app: pipx install copier
  • To use as a library: pip install copier
  • Has a simple Python API
  • Main advantage: Can update existing projects
  • Runs from basic YAML files

Jennifer #3: Pandarallel - run pandas apply in parallel!

  • simple install `pip install pandarallel [--upgrade] [--user]``
  • import from pandarallel import pandarallel
  • initialise pandarallel.initialize(), set progress bar BOOL, set number of workers … (defaults to all cores)
  • just use parallel_apply where you’d usually put apply

Brian #4: Stop Using Print to Debug in Python. Use icecream Instead

  • Khuyen Tran
  • print(f``"``{x=}``"``) is better than print(f``"``x: {x}``"``) but it’s still a lot of typing.
  • With icecream, you can type ic(x) insted and git this nice output: ic| x: 5
  • It’s less typing and just as nice.
  • There’s more.
    • ic() with no arguments logs the file, function, line number when it’s hit. Easy program flow tracing without a debugger.
    • You can configure it to do this cool context thing even if you do pass in a value to print.
    • You can configure custom prefix formatting with a callback function, so you can include the time or the user that’s logged in, or whatever else state you want to track.
    • Since all output is prefixed with ic|, you can see it easily
    • Writes to stderr by default, so it doesn’t muck up stdout stuff
    • Clean it out of your code by searching for ic() statements. If you have normal print statements in your code, you don’t want to use print for debugging also.

Michael #5: HTMX: Dynamic and live HTML without JavaScript

Jennifer #6: PyLDAvis - Interactive Topic Model Visualisation

  • Port of LDAvis R package (does this mean PyLDAvis is a wrapper? A translation?) by Carson Sievert and Kenny Shirley
  • User calls pyLDAvis with fitted model made with your favourite library (eg Gensim, sklearn, GraphLab)
  • Outputs include:
    • term frequency within topic bar chart
    • term frequency within whole corpus bar chart
    • next to each bar is a word. You hover over the word and the topic circles adjust size to reflect representation of that term in that topic.
    • topic circles - one for each topic, whose areas are setto be proportional to the proportions of the topics across the N total tokens in the corpus
    • term-topic circles, with area proportional to the frequencies with which a given term is estimated to have been generated by the topics of whole corpus
    • slider to adjust relevance metric (0 = terms very specific to currently selected topic; 1 = terms frequently seen in many topics).

Extras:

Brian:

  • I’m also speaking to a group of NOAA people next week.
  • I’m speaking the Aberdeen Python User Group on the 10th of Feb. It’s virtual, so everyone can come.
  • Excited about both. My kids are more impressed with the NOAA thing. It’s fun to impress your kids.

Michael:

Joke:

Engineer helping a designer

https://twitter.com/EduardoOrochena/status/1306944019268861953


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