Python virtual env

Intro

I’m getting started with Pyton and little bit confused with venv so I want to write black on white what I understood so far. I use Windows 10 22H2 but the process should be similar on other Windows versions or OSes. I suppose Python 3 is installed, up and working.

In a terminal

• mkdir my_project
• cd ./my_project
  • Type “cd my” then strike TAB
• py -m venv .\PrjVEnv
  • This may take few seconds
  • This creates, among other things, a subdirectory named ./PrjVEnv
  • Most of the time you will see : py -m venv .venv

• ls
  Just to check that the ./PrjVEnv subdirectory has been created

• code .
  Don’t forget the dot
  This launches VSCode “in” the current directory

   

In VSCode

• CTRL + SHIFT + P
• Python: Select Interpreter
  • If needed start to type “Python” then the different options should be listed.

   

• Python 3.10.7 ('PrjVEnv':venv)./PrjVEnv/Scripts/python.exe
  • Or, if you run another Python version pick the one listed with the “(‘PrjVEnv’:venv)”
  • This is the interpreter running within the context of the Python Virtual Environment

   

• CTRL + SHIFT + ù
  • To open a new Terminal within VSCode

   

• python -m pip install numpy
  This installs the lib needed by the project

   

Done!

Just to make sure…

• Enter some code

import numpy as np

def MyFunction():
  A = np.array([0, 1, 2, 3])
  print(A.shape, A.size)

if __name__ == '__main__':
  MyFunction()

• CTRL + S Save the code

• Set a breakpoint

   

• F5 Select “Debug the currently active Python file”

   

• F10 To step over the breakpoint when you reach it
• Inspect the variables etc.

   

• F5 To let the code ends

   

• If additional libs are needed, as before, add them from the VSCODE console
• python -m pip install scipy For example

Voilà, I hope this helps.