NicerPDB

A terminal frontend for Python's pdb debugger, powered by rich.

Install

pip install git+https://github.com/Hedwyn/nicerpdb.git

Features

• Syntax-highlighted code display
• Improved variable inspection
• Enhanced stack traces
• Pretty-printed expressions

Usage

As an entrypoint

Simply substitute pdb by nicerpdb:

python -m nicerpdb <script_path>

Invoke automatically on breakpoint

If you want nicerpdb to be invoked on a breakpoint() without using it explicitly as entyrypoint, you can set the PYTHONBREAKPOINT environment variable which allows customizing the debugger called on breakpoint:

• Set it persistently in your current session with:

export PYTHONBREAKPOINT=nicerpdb.set_trace

• Or for a single command using the usual environement variable syntax:

PYTHONBREAKPOINT=nicerpdb.set_trace python <script_path>

Invoke automatically on test failure with pytest

pytest provides the --pdb option to invoke automatically pdb in post-mortem mode on test failure. nicerpdb provides a pytest plugin to provide the same functionality; replace --pdb by the following flags -p nicerpdb -s (-p loads a pytest plugin, -s disables output capturing so that the debugger can interact with the terminal).

Extensions to PDB

Additional commands

• l / list: support passing an integer defining the number of lines to show.
• sh / shell: runs a shell command and display the output within the debugger session. There are a few variants:
  • psh/ prettyshell: uses syntax highlighting on the output.
  • fsh / fshell: allows expanding variables from current Python frame's locals or globals into the shell command. The syntax is %variable_name. Please mind that $ syntax (e.g. $variable_name) is already used for PDB's builtin convenience variables.
  • pfsh / fpsh / fprettyshell: enables all of the above.