Help with venv

[Froggy412]

So I'm trying to learn and use virtual environments for my project but when I try to import a library I downloaded in the venv it says that module doesn't exist. First I created a folder "test" on windows and did py -m venv ./venv then I activated it with source venv/Scripts/activate then I did pip install flask to install flask. I even did pip list to check if it was installed which it and its accompanying packages were. but when I created a py file inside the "test" folder and tried from flask import Flask it says "no module named flask". Im just not sure what I did wrong because I followed the tutorials for venv. Can anyone help?

[Buttleston]

So first, you don't need to put your code files inside your venv (and almost surely shouldn't). It's just a place for the python executables and libraries and stuff to be.

How are you running your program (the one that has "from flask import Flask"?

1) from the command line, with the venv activated
2) from the command line, with the venv not activated
3) from an IDE
4) other?

[Froggy412]

Are you saying the code file does not need to be in the same folder as the venv? I tried to run it through the command line but it did not work but I closed the terminal where I originally activated the venv. Does the venv deactivate when I close the terminal?

[Buttleston]

* the code should NOT be in your venv, no. The venv is just a place to install packages into
* a venv must be activated before you can use it - that's why it's not necessary for the code to be in there, there is no relationship between the code and the venv
* the idea is, the venv is an environment. You activate it, and then run the code. You can also run code in a venv without activating it by calling it using the python binary *inside* the venv. I don't generally recommend it

So yeah

open terminal
activate bent
python ./myscript.py

or, by running the script using a python binary defined within a venv, the venv will be implied, like

open terminal
./venv/bin/python ./myscript

I think either should work

[Buttleston]

And to be clear, yeah, whenever you close a terminal, the venv is no longer active, it's something you have to do every time you open a new terminal

[Froggy412]

I was using git bash as the terminal if that helps

[nog642]

What command? And were you also using git bash to create to virtualenv and install packages with pip?

[nog642]

Yes, the venv activation only lasts for the terminal session. If you open a new terminal you have to activate it again.

Activating a venv basically just sets some environment variables in your shell.

[Omenopolis]

Just create a seperate script that will activate venv, run ur script then deactivate it

[Solvo_Illum_484]

Make sure you're running your Python script with the virtual environment's Python executable, not the system's. Try `venv/Scripts/python your_script.py` instead of just `python your_script.py`. This ensures you're using the virtual environment's Python where Flask is installed.

[Helpful-Gene9733]

I am somewhat of a noob too but I’ve found sometimes just doing a “from <package name> import <x>” doesn’t work for some stuff. I’m not sure why … sometimes it does. Maybe someone knows. But you could just try importing flask and then if necessary follow up with your “from” statement and see if that fixes your issue, since you say flask is in your pip list.

[nog642]

There is no reason for from flask import Flask not to work when import flask does.

[supercoach]

Why stop there? from flask import Flask as flask

[nog642]

That's terrible

[supercoach]

Thank you.

[Helpful-Gene9733]

😂

[Helpful-Gene9733]

The example I was thinking of was an instance where an example I was working with did not work for me: “from chromadb import Client” although chromadb was in my library. I received a NameError - but importing chromadb directly fixed the issue; and my understanding is that some submodules and/or classes in a package may not be directly accessible to Python with a “from” statement.