How does the rest of the world manage to survive without venvs? Config files in the directory. Shocking, really :-)))
The problem is, that would require support from the Python runtime itself (so that `sys.path` can be properly configured at startup) and it would have to be done in a way that doesn't degrade the experience for people who aren't using a proper "project" setup.
One of the big selling points of Python is that you can just create a .py file anywhere, willy-nilly, and execute the code with a Python interpreter, just as you would with e.g. a Bash script. And that you can incrementally build up from there, as you start out learning programming, to get a sense of importing files, and then creating meaningful "projects", and then thinking about packaging and distribution.
Node or PHP also work like normal Unix programs...
I wonder what good you think insults do? I could insult your use of English for example but would that make my argument better?
> PHP and node were not developed as general purpose scripting languages for use at the commandline and are very commonly used for specific purposes so there's no need for them to be like python.
Perl, Ruby, Lua, I can keep going. You're just nitpicking. Practically only Python uses the venv [1] approach from all the programming languages I've used.
[1] Manual activation needed, non portable pile of dependencies per project (by design, fairly sure the documentation mentions this is not a supported use case - even across quasi-identical machines !!!), etc. I stand by my decision to call venvs a "fractal of bad design".
As things are, I can share a venv with several projects, or have one for my account if I don't want to break the system tools. I can even write a trivial bash function to activate a venv automatically based on whether a venv exists in my project. It's so trivial to do and yet generates all this discussion.
As for non-portability that's the most specious and pathetic argument of the lot. who can bother to make every library portable to every distro....? what is the point of distros if one demands that one can run the same binaries everywhere? This is what containers were invented for. If you need the latest versions you might just, heaven forbid, have to compile something and fight with the problems of running it on distro that it wasn't developed on.
Their single advantage over Python is that they are able to work fine without virtual environments, as they just load libraries from a relative path: That way, you can copy-paste a project directory, move it to another system with a copy of the interpreter binary, and… run the software. There is nothing clever about that; I’d even say Python's way of magically configuring a shell just to be able to locate files is the "clever" solution that nobody asked for!
Python venvs literally f*ed up the simplest form of deployment on the planet, scp. Yes, we have more complex solutions like Docker, another abomination (the software itself). Docker was invented in big part due to Python (not only, but it was a big factor).
Again, I use venvs. They're ok. But they're a stupid semi abstraction.
python -m venv --copies .myvenvdir
There's nothing nice about this but it does protect you from a lot of issues where it might seem to work and then behave unexpectedly. e.g. if you had a different python on the destination.
Docker doesn't just help with scripts - it also manages the problem of binary compatibility with C and C++ (and whatever) libraries. You may not have had this problem with C/C++ code so you might imagine it's all about python but I can only say it's a misery that the C/C++ crowd have been suffering with for a very long time. How does one support 3 distros each with a different version of libffmpeg installed when you're making a media player? Sometimes there's a lot of "#if FFMPEG_MAJOR > 3" in the code to cope with it.
The distro developers build each package with a bunch of patches to adapt them to the distro they're in.
It's bad enough for the distro developers to curate all this when it's their job but with python devs are living in a more minimally curated world and in some applications like ML are now dealing with wide and deep dependency trees that rival a distro.
IMO perhaps "someone" should come up with some new distributions where they make everything work together.
So a lot of other major ecosystems are just self contained. All the "big" libraries are portable and written in the language itself, so they rarely plug into C/C++ (aka distribution/OS dependencies).
So Docker was basically built primarily for slow programming languages and I guess in a weird way, for C/C++, as you say? :-)))
For .pth files to work, they have to be in a place where the standard library `site` module will look. You can add your own logic to `sitecustomize.py` and/or `usercustomize.py` but then you're really no better off vs. writing the sys.path manipulation logic.
Many years ago, the virtual environment model was considered saner, for whatever reasons. (I've actually heard people cite performance considerations from having an overly long `sys.path`, but I really doubt that matters.) And it's stuck.
source - why are we using an OS level command to activate a programming language's environment
.venv - why is this hidden anyway, doesn't that just make it more confusing for people coming to the language
activate - why is this the most generic name possible as if no other element in a system might need to be called the activate command over something as far down the chain as a python environment
Feels dirty every time I've had to type it out and find it particularly annoying when Python is pushed so much as a good first language and I see people paid at a senior level not understand this command.
Because "activating an environment" means setting environment variables in the parent process (the shell that you use to run the command), which is otherwise impossible on Linux (see for example https://stackoverflow.com/questions/6943208).
> why is this hidden anyway, doesn't that just make it more confusing for people coming to the language
It doesn't have to be. You can call it anything you want, hidden or not, and you can put it anywhere in the filesystem. It so happens that many people adopted this convention because they liked having the venv in that location and hidden; and uv gives such venvs special handling (discovering and using them by default).
> why is this the most generic name possible as if no other element in a system might need to be called the activate command over something as far down the chain as a python environment
Because the entire point is that, when you need to activate the environment, the folder in question is not on the path (the purpose of the script is to put it on the path!).
If activating virtual environments shadows e.g. /usr/bin/activate on your system (because the added path will be earlier in $PATH), you can still access that with a full absolute path; or you can forgo activation and do things like `.venv/bin/python -m foo`, `.venv/bin/my-program-wrapper`, etc.
> Feels dirty every time I've had to type it out
I use this:
$ type activate-local
activate-local is aliased to `source .local/.venv/bin/activate'
$ cat .local/.gitignore
# Anything found in this subdirectory will be ignored by Git.
# This is a convenient place to put unversioned files relevant to your
# working copy, without leaving any trace in the commit history.
*
If you know anyone who's hiring....
> which is otherwise impossible on Linux
Node, Rust, etc all manage it.
> Because the entire point is that...
I just mean there is a history of Python using overly generic naming: activate, easy-install. Just feels weird and dirty to me that you'd call such a specific things names like these and I think it's indicative of this ideology that Python is deep in the OS.
Maybe if I'd aliased the activate command a decade ago I wouldn't feel this way or think about it.
$ (bash -c 'export foo=bar && echo $foo')
bar
$ echo $foo
$
Similar mindset to the original creators of venv, I imagine :-)
The git model is based on automatic detection of the .git folder, by having it in a location determined by convention. Many higher-level tools in the Python ecosystem have provided analogous handling of virtual environments over the years. Uv is doing it now; historically pyenv was used for that sort of thing, for example.
But when I said "which is otherwise impossible on Linux", I was specifically referring to the setting of environment variables, because OP asked why an activation script had to be sourced, and the reason is because that's what "activation" is.
This is a model that enough people liked using many years ago, to become dominant. It creates the abstraction of being "in" the virtual environment, while giving you the flexibility to put the actual file tree whereever you want.
uv has increased my usage of python for production purposes because it's maintainable by a larger group of people, and beginners can become competent that much quicker.
Surely the effort of programming the actual code is so significant that starting a tool is a minor issue?
Why are people not using the system python? Perhaps it's too old or not old enough for some library that they have to use. This suggests there's a lot of change going on at the moment and it's not all synced up. I also suspect that people are using a very great number of different modules that change incompatibly all the time and ontop of that they need binary libraries of various kinds which are quite difficult to build and have all their own dependencies that python cannot install itself.
Rust has the advantage that they can build a world more completely out of rust and not worry as much about what's on the system already.
I'm glad uv is helping people.
If you're on a "stable" distro like Debian or Ubuntu LTS, that can be somewhere around 5 years old at the end of the stability period. And your system probably depends on its Python, so if you need a newer version of a library than the system's package manager provides you can't update it without risking breaking the system. Python itself has added several very nice new features in the last few versions, so anyone stuck on Ubuntu 22.04 LTS with Python 3.10 can't use newer Python features or libraries through their system's package manager.
The other reason is because it's the only approved distribution your company's IT department allows. Or the only distro your company's mandatory "security" software runs on. Etc. It's dysfunctional, but "enterprise" tends to mean "ancient 'stable' distribution if Linux is allowed at all" which in turn means "system python isn't useful, even if using it wouldn't break the system".
I also value my time and life and some degree of standardization.
A language grows on it's ability to create beginners, not to make the people who have learned it the harder way feel special at the expense of others.
Fortunately uv got written and we don't have a problem. I don't have to use it but I can when I want to.
If uv makes it invisible it is a step forward.
not that it's great to start with, but it does happen, no?
Installing a particular node version also becomes as easy as
fnm install 24Either the package manager is invoked with a different PATH (one that contains the desired Node/Java/whatever version as a higher priority item than any other version on the system).
Or the package manager itself has some way to figure that out through its config file.
Or there is a package manager launch tool, just like pyenv or whatever, which does that for you.
In practice it's not that a big of a deal, even for Maven, a tool created 21 years ago. As the average software dev you figure that stuff out a few weeks into using the tool, maybe you get burnt a few times early on for misconfiguring it and then you're on autopilot for the rest of your career.
Wait till you hear about Java's CLASSPATH and the idea of having a SINGLE, UNIFIED package dependency repo on your system, with no need for per-project dependency repos (node_modules), symlinks, or all of that stupidity.
CLASSPATH was introduced by Java in 1996, I think, and popularized for Java dependency management in 2004.
Activating a venv is just setting a few environment variables, including PATH, and storing the old values so that you can put them back to deactivate the environment.
The venvs created by the standard library `venv`, as well as by uv (and by the third-party `virtualenv` that formed the original basis for `venv`), also happen to include "activation" scripts that manipulate some environment variables. PYTHONPATH is not among these. It manipulates PATH, so that the venv's symlink is on the path. And it may unset PYTHONHOME.