unresolved import 'PyPDF2' code example

Example 1: why always appear errors in vscode while importing the library

{
  "version": "0.2.0",
  "configurations": [
    {
      "type": "node",
      "request": "launch",
      "name": "Launch Program",
      "program": "./app.js"
    }
  ]
}

Example 2: python unresolved import vscode

# I use pylance now. I added this. Problem solved.
"python.analysis.extraPaths": ["./path-to-code/"],
# I tried this before, but not working. 
"python.autoComplete.extraPaths": ["./path-to-your-code"],