PyDev Client

This project is still in beta, so it may require some extra actions to get it running. Your mileage may vary.

PyDev (https://github.com/fabioz/PyDev.Debugger) is the Python debugger used in PyCharm and Eclipse’s PyDev-plugin. It supports debugging multi-threaded applications such as Django or CherryPy -based projects.

This repository contains a command-line client for PyDev, and realgud-bindings for using it inside Emacs.

Features:

Implemented commands:

Parameters and outputs are similar to those of trepan3k-debugger.

command	short	description
start		start the debugger
step	s	step into
next	n	step over
return	r	step out
break	b	add breakpoint
delete		remove breakopint
continue	c	continue execution after break
eval	e	evaluate an expression
exit/quit	^D	exit the debugger (server will be killed with SIGTERM)
list	l	list file contents around current position

Features to be implemented:

• Enabling/disabling breakpoints
• Moving up/down frames
• Restarting the debugger
• Breakpoint conditional expressions
• Better input handling, arrow keys not working since we are using readline for now. Reason for using readline instead of raw_input is that readline can be used with select.
• Tests
• Better handling for multiple threads, currently the client selects one thread as an active one. A thread that stops at a breakpoint is always selected as active
• Supporting multiple simultaneous sessions inside emacs, requires some way to get a free port number for the server and the client to become aware of it.

Python client

Installation:

python setup.py install

This will install the client, and PyDev debugger daemon as a dependency.

Usage:

Start the daemon:

pydevd --port port --server --file filename [arguments ...]

or

pydevd --port port --server --module --file filename [arguments ...]

Start the client:

pydevc --server 127.0.0.1 --port port

The client has connected to the remote debugger when you see prompt (pydev).

Realgud extension

Installation:

Add following to your init file (requires use-package to be installed):

(use-package realgud-pydev
  :load-path "/path/to/pydev-client")

Usage:

M-x realgud:pydev-current-file

or

M-x realgud:pydev-module

Virtual environments work as expected at least with pyvenv, if the python modules have been installed to the specific virtual environment.

The pydevd-server will be opened in a separate process, and it’s output will be shown in a separate emacs buffer. This makes it easier to use the command-line interface when the output of the debugged program does not mess up the interface.

Compiling PyDev debugger

To get much more performance from the debugger server, you can compile it with Cython:

1. Clone the PyDev repository from https://github.com/fabioz/PyDev.Debugger
2. Ensure you have cython installed

   pip install cython
       

3. Compile the library

   python setup_cython.py build_ext --inplace
       

4. Install the library

   pip install .