debug-third-party-packages.md

Step into code of third-party packages with debugger

Problem

By default, the VS Code debugger does not step into the source code of third-party packages.

• e.g., if you use import pandas as pd and want to step into pandas source code
• or import my_package when my_package is installed as a package in your PYTHONPATH or site packages
• the VS Code debugger - by default - will only step through my_package if the source code is in the the top-level root of your repo, which is not always the case.
• This is troublesome if you want to debug your own package that is contained in, say, a ./src directory.
  • E.g., say you've pip-installed your package from source in editable mode (pip install -e .). You still want to be able to step through the code using your IDE's debugger.

Solution

• for VS Code, set justMyCode parameter to false in your debugger launch.json config
• in PyCharm, there is both a Step Into My Code and Step Into button (PyCharm docs)
• less user-friendly but works anywhere: use pdb
  • tutorial via RealPython
  • Python pdb docs)

// ./.vscode/launch.json
{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [

        {
            "name": "Python: Current File",
            "type": "python",
            "request": "launch",
            "program": "${file}",
            "console": "integratedTerminal",
            "justMyCode": false,
        }
    ]
}