How can I debug a python code in a virtual environment using VSCode?

Question

EDIT

Using VSCode, I had an issue while debugging in a virtual environment that have different packages which are not installed in the base environment. After activating the environment with the command activate my_env, I can use the packages in the environment with usual python command as python main.py. But while debugging, I can't use the packages which are only installed in my_env. How can I debug a python code in a virtual environment using VSCode?

This is this the summary of the question. The rest has some specific info about my case.

BEFORE EDIT

I am trying to use xmltodict package with a simple code using visual studio code.

import xmltodict

with open('C:\\Users\\user\\foo.xml') as f:
    db_dict = xmltodict.parse(f.read())

print(db_dict)

I have a virtual environment named my_env, and I installed xmltodict package in it. When I activate the environment with activate my_env, this code works fine. But, when I try to use vscode debug option, it gives No module named 'xmltodict' error. Becuase vscode debug button opens new cmd and run the debugging command in it, I stopped debugging and typed activate my_envin that cmd and tried to debug again, but still it can't find the module. Also, I tried jupiter notebook in vscode, it also doesn't see the package.

I see that import xmltodict is underlined with red in vscode and it says Unable to import 'xmltodict', but it works when I run it normally from cmd. This happens sometimes for other modules and I don't know why. I installed xmltodict module using pip, maybe it causes that.

I am using Visual Studio Code 1.30.1 with Anaconda Python 3.7.1 on Windows 10.

How can I debug a python code in a virtual environment using VSCode? I saw this question, but I don't think it is exactly what I want?

Solution 1

Set "python.pythonPath" to point to the interpreter in the virtual environment that you want to use.

Solution 2

I am using venv for creating virtualenv, and VS code to debug the code.

I found we don't have to create a launch.json file but add settings.json under {project}/.vscode/ folder. My settings.json is as below:

{
"python.testing.unittestArgs": [
    "-v",
    "-s",
    ".",
    "-p",
    "test_*.py"
],
"python.testing.pytestEnabled": false,
"python.testing.nosetestsEnabled": false,
"python.testing.unittestEnabled": true,
"python.pythonPath": "/Users/hhh/project/bin/python"
}

I can debug the project and run the unit test as well. Hope it will help you.

Comments

[Alperen]

Thanks. If we add python.pythonPath to settings.json, it works. But, I just want to add another way which is making the same thing. Use the Python: Select Interpreter command from the Command Palette (Ctrl+Shift+P) and select the python interpreter that belongs to the new virtual environment. I tried this one at the beginning but I couldn't see a python interpreter for new environment in the selection list. Restarting VSCode fixed the situation fro me. After restart, I could see the python interpreter for the new environment in the selection list.

[Brett Cannon]

@Alperen glad it worked! Yes, the Select Interpreter command actually writes out the setting for you. And the newest release of the extension should detect a new virtual environment in the directory, but we have to notice it which isn't necessarily immediate.

[Burakhan Aksoy]

@Alperen I directly used your method and worked like a charm! Thanks ~

[Ilya Pukhov]

That explains alot. (sarcasm detected)

[Timo]

It is unclear in which file to put the python path key value store in your answer. I guess it should go in the project local settings.json.

[simkusr]

for me in vscode v1.66.1 I had to add additional flag "justMyCode": false in my ./.vscode/launch.json so it would work properly, after this flag, it started working and I was able to debug libraries also :)