 Miscellaneous thought about Python development environment usability: maybe a good focus could be ensuring that developers don’t have to understand the concept of their $PATH in order to debug problems with their environment I’m not sure how that could be achieved, but it’s an interesting angle to think about the problem 24 comments
 @simon That is one of the benefits of running in a self-contained dev container. You can be sure that your system (global installs, env vars, etc) don't interfere with the dev environment. I always wondered if there is an iteration on python's venv concept where the venv would also restrict filesystem paths, env vars, and more. @simon What was the specific problem? I honestly don't remember the last time I had a PATH problem, but I'm sure I have a blind spot here. @brettcannon for the problem I just had it was that thing where I create a brand new pipenv environment and install pytest into it, but when I run pytest it runs a globally installed binary instead - I had to quit out of and re-enter the environment to get the environment-local pytest to run (which could then see my dependencies) It reminded me how much knowing what a PATH is matters for figuring out errors like that  @simon @brettcannon also it's hard to describe the common new-user failure mode, which is "something doesn't work, or it behaves weirdly with tool X, so I install tool Y because maybe that one works". X, Y, Z, A, B C all append a little bit of stuff to your ~/.zshrc or whatever, scattering $PATH configurations into a bunch of different locations that make every IDE and terminal function differently, and even if it's all eminently comprehensible, unwinding is a tedious nightmare @simon So I take it you don't run pytest via `python -m pytest` but instead via `pytest`? @brettcannon huh... that's the case, but now you mention it there's no reason I shouldn't start a habit of using "python -m pytest" instead @dabeaz @brettcannon I've upgraded all of my cookiecutter templates to use "python -m pytest" instead of just "pytest" now: https://github.com/simonw/python-lib/issues/9  @simon @dabeaz @brettcannon Python‘s. venv is like Marvel‘s Multiverse. No one ever is positively surprised by any of it.💁🏻♂️ What if Python shipped a standard library module that diagnosed this stuff in as much detail as possible for you? So you could run something like: python -m debugenv And it would print out a whole bunch of useful stuff about what your PATH is, your Python path, what version, any other versions it can find in common locations, if you are in a virtual environment, links to tutorials that will explain more - that kind of thing @simon I wrote something that does a little bit of this: https://github.com/nedbat/pydoctor @simon something along these lines is quite literally on my plate for the next few weeks of free time at work  @simon I started to write that once. The root problem is that the Python run time could be anywhere on the machine, but is likely at a few know places. Or it is at 130 places because that is how many vens are on the machine. @simon This would have saved me two to three hours today. it really needs to come to life. @simon I’m sure you’ll hear about a number of these tools today, but for work I made a less Python-specific environment report tool, which handles things like HPC system modules, pip, conda, $PATH: https://github.com/minrk/envreport . It errs on the side of “entirely too much information, send this to support,” probably not very manageable for most directly affected individuals. @simon Thinking about my very long set of instructions for setting up a Python environment, I realize that a lot of it could be called $PATH problems. @simon I know @wsvincent has spent a lot of time battling this for his Django for Beginners book. (“First learn some esoterica…”, it feels like.) @capotej sadly I don’t think that works - I think it may be one if those weird pieces of trivia that loses people entirely (A lot of people these days don’t understand files and folders! I’d rather invest my education efforts in things like that https://www.theverge.com/22684730/students-file-folder-directory-structure-education-gen-z) |
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(This thought brought to you after several lost minutes where it turned out I had the wrong PATH and that’s why tests were failing in weird ways)