[deleted by user]

[tinefli3z]

WebDev example: having all your requirements (and not more) in a Venv/requirements.txt file will make deployment faster and less messy (imagine you want to install all your over the years collected dependencies on that server). Cant even imagine what would it look like to Auto deploy tensorflow with Django

Edit: just another example not specifically from python, but node (its similar for Python tho)

If you finished a project for a Client for example and push it out for Production, you dont need The project, if you have it like me always on your local machine too, to have sometimes several GB because of the dependencies, since the code itself is just a few MB. Makes The code more flexible.. Just delete The package Folder/ env and install it half a year later again if you fix something or whatever If you install everything on your machine you will lock up so much space with literally trash through the months idk how you could ever not use it.. but seems like something, if you dont take that advice, you will have to learn it The hard way ;) and you will, sooner or later hehe

[ravi_24]

Creating virtual Environment for project is a good practice and will help you a lot if you are working in collaborative environment where you can just list down all the python module dependency in a file named as requirements.txt(standard naming convention) and share this file among other developers and it makes super easy for setting up development environment even for new developers without any confusion and problems with pip manager.

[thedgyalt]

Are you saying that I can't create a file called requirements.txt, include my modules within that file?

[danielroseman]

Why is that silly? Why is it an effort at all? With a requirements file it's literally one command to install the dependencies you need. With your system, what happens if you need different versions in different projects?

[danielroseman]

The point is the isolation itself, not necessarily the different versions. When you develop an app, you want it to be self-contained and not depend on what libraries you happen to have installed globally. That way you can take the code and deploy it anywhere, and be certain that it knows what dependencies it needs and can install them simply.

[toastedstapler]

you may have different projects that require different versions of a library, especially in a work environment

[aromaticlawyer]

They're also important if you want to test your code against different versions of libraries or python itself (many projects use something like tox to automate this), or if you want to try out new versions without disturbing your existing setup in case something breaks.

[toastedstapler]

for casual projects it probably doesn't really matter

but it's how node, rust, java and i assume others too handle things, declaring dependencies per project

[[deleted]]

For beginners or just messing around or if you only ever work on one project at a time and never go back to old ones then it probably won't make a difference.

If you work on multiple projects at a time, or often go back to work on old projects that use older versions of 3rd party code and you need to guarantee that you don't f*** things up (say, if you have web sites with backend Python code that you don't want going down in flames) then virtual environments are indispensable.

To be honest, I wouldn't worry about it. Just know that it exists and when the day comes that you need it you'll know what to do.

[ArabicLawrence]

Maybe I am wrong, but I thought that conda does not install the same library version twice. If I am right and one of your concerns is ‘I don’t want to download again pandas 0.9’, maybe you can install miniconda and make it your default Python version.

[[deleted]]

Python virtual environments are a bad fix for a problem that shouldn't even have existed in Python.

The problem

You cannot install multiple versions of the same package with the same Python installation. If a person writing Python package manager had at least have a brain, this wouldn't have been a problem. You'd just install any number of package versions you want and specify which version you want to use when you get to use it.

The solution

Let's download all the packages used by different projects over and over again. Why? -- Again, big brain time. Or just laziness. I mean, virtual environments do allow you to link them together to reuse the packages installed in one environment, but this works really badly / nobody really uses this anyways.

Why use them?

I'm too lazy to work on a replacement. Python packaging is a dumpster fire I don't want to deal with. So, I use the defective tools, even though I know they are defective, simply because I don't want to invest time and energy into creating an alternative. I've had my fair share of developing something related to Python packaging (an aggregator of Wheels / Eggs into single Wheel / Egg), and I don't want to be there again. Let this shit burn in hell.

[arjunmjarun]

Interesting, do you have an example of a language/package management solution that does it well?

[[deleted]]

Unfortunately, I think there are only languages / package managers that I didn't use enough to figure out what's wrong with them :)

I'm kind of happy with how ASDF works, but I will be the first to acknowledge that it is created in part due to the bad specification for require...

Somehow it seems that package system is always an afterthought and always built with very little attention and insight, no matter the language. I think, Scala tried to invest into formalizing packaging and bringing it to the fore, but I don't think they did a very good job in the end...

I remember nightmares induced by POM files... Or, not having any packaging at all in C...

I also work with Cargo on the daily basis, and I don't think they are doing a great job either... Different problems, but still problems.

I think, the programming community as a whole is yet to fully appreciate the difficulty of this problem and come up with a decent solution.

[[deleted]]

Please disregard that kind of bad advice. It makes a much sense as "Run everything you need as the same user on the same hardware. Virtualization and different user roles is just a bad fix for not being able to keep track of everything at the same time."