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by bioballer 866 days ago
Python isn't oriented around defining and validating data.

For example, something like: "this number is be between 1 and 10" means you have to come up with a novel way to add validation, because it isn't built into the language.

Also, Pkl is meant to be usable everywhere. General purpose languages tend to be tied to their own ecosystem--imagine telling a Go developer that they need to install Python, set up virtualenv, and run pip install so they can configure their application. We'd like Pkl to be a simple tool that can be brought anywhere, and easily integrated into any system.

3 comments

> For example, something like: "this number is be between 1 and 10" means you have to come up with a novel way to add validation, because it isn't built into the language.

No need for a novel mechanism - there are plenty of available solutions to add validation to python

> imagine telling a Go developer that they need to install Python

Pkl doesn't come preinstalled on machines - so you'll have to install it as well

> set up virtualenv, and run pip install so they can configure their application

This is the real friction point, but is it a bigger friction point than having to adopt yet another DSL?

> This is the real friction point, but is it a bigger friction point than having to adopt yet another DSL?

Yesterday, I created a virtualenv, then ran `pip install`, only to see it fail. I found out that even `pip --version` was failing. I discovered that running `python -m ensurepip --upgrade` would fix pip. It did fix pip, but `pip install` still didn't work properly. I figured out that pip was reporting a different version of python than the one virtualenv is using. Running `python -m pip install --upgrade pip` upgraded pip, which should have been accomplished with the previous ensurepip command. Finally, everything was working properly.

I experienced these problems after years of experience in python. To answer the question. Yes, it's worth adopting yet another DSL than using python.

Did you activate the virtual environment?

For all the flak python gets, dependency setup is pretty simple if you're not flailing around aimlessly

  python3.12 -m venv --copies --clear --upgrade-deps ".venv"
  source ".venv/bin/activate"
  python -m pip install --upgrade pip setuptools wheel
  python -m pip install --editable .
Yes, I had activated the virtual environment. Thanks for the guide. It works without problems. I had used `virtualenv venv -p /usr/local/bin/python3.12` in my setup. Yours seems to be a better way.
That right there is the main problem with python dependency management - too many damn ways to do the same thing.

And to think "There should be one-- and preferably only one --obvious way to do it." is in the Zen of Python...

assert x >= 1 and x <= 10, "x is out of the allowed range"

What novel way to add validation in python?

This made me realize that Go actually succeeds at being more pythonic than python.

I'm also incredibly high.

High or not, you're 100% correct.

Have a look at PEP 20 – The Zen of Python.

Python is actually horrible at following it, Go doing a much better job.