When I did not install the module "flask" in the Python environment currently used in VSCode:

Please use the command "pip --version" to check the source of the module installation tool "pip", the module is installed at this location:

Then, we can use the command "pip show flask" to check the installation location of the module "flask": (It checks whether the installation location of the module is consistent with the Python environment displayed in the lower left corner of VSCode.)

If the "reportMissingModuleSource" message is still displayed here, please reload VS Code.

(F1, Developer: Reload Window)

I had the same error. Changed my system python by doing the following in VS Code: Under the view menu select 'show command pallet'. One of the commands you can then select from the command palette is 'Python: Select Interpreter'. Selecting this option will allow you to choose which version of python to use.

When I did not install the module "flask" in the Python environment currently used in VSCode:

Please use the command "pip --version" to check the source of the module installation tool "pip", the module is installed at this location:

Then, we can use the command "pip show flask" to check the installation location of the module "flask": (It checks whether the installation location of the module is consistent with the Python environment displayed in the lower left corner of VSCode.)

If the "reportMissingModuleSource" message is still displayed here, please reload VS Code.

(F1, Developer: Reload Window)

I was having the same problem, I messed around a lot reinstalling things so I'm not 100% sure what the perfect solution is but this is what finally worked for me.

View -> Command Pallete -> Python: Select Interpreter -> Select the version that says 'Global'

Then follow the same steps but instead select the version that says 'Recommended'.

I am assuming it somehow reinitialized the version of python I was trying to use.

You need to add your current working directory to the python search path. This can be done with an environment variable:

export PYTHONPATH=.

Alternatively you can do it from within Python. I usually put this in my conftest.py file in my tests folder, which is executed when pytest starts up.

import sys
from pathlib import Path
path = Path(__file__).parent.parent  # i.e. the folder above the tests folder, which has app
sys.path.append(path)

The VS Code error is a separate issue. It sounds like you might not have the correct Python environment selected. See https://code.visualstudio.com/docs/python/environments

The problem seems to be that when you run your flask script, the environment that it uses (anaconda) doesn't have the flask_sqlalchemy package installed, which makes the script fail, but when you check whether it is or it isn't installed, you do so in the virtual environment venv where it is indeed installed.

1. Check for the current Python Interpreter VSCode is using Ctrl+P.

2. Add your virtual environment PATH where your module is installed in 'C:\Users\<username>\.virtualenvs\<virtualenvname>\Scripts\python'.