xtrace /

Filename Size Date modified Message
225 B
1.8 KB
573 B
7.1 KB

This module prints function trace to stdout from the moment it is called:

import xtrace

It is also possible to call xtrace as module from the command line:

python -m xtrace <script.py> [param] ...

or use as a standalone script:

python xtrace.py <script.py> [param] ...

The output format is inspired by Xdebug function traces and will likely to merge with it http://xdebug.org/docs/execution_trace to be compatible with PHP inspection tools. But I didn't have enough time to polish it, so feel free to send a patch if you know how to bring them closer.

This code is released into public domain. Enjoy!


  • 0.5 - fix major crash when function in executed script tried to read variables in its global scope
  • 0.4 - added beep function which beeps in DEBUG mode when excited
  • 0.3 - fix AttributeError when running from console (issue #2)
  • 0.2 - added version info, support running from command line, moved main functions into a class to isolate used variables in local namespace
  • 0.1 - initial release


Amaury Forgeot d'Arc, for valuable insight into Python internals


To see various internal events that xtrace produces on top of standard data provided by Python, enable DEBUG option:

import xtrace
xtrace.DEBUG = True

This will call beep functiton for every interesting event. Feel free to override it (monkeypatch) with your own to filter messages, forward, etc.

Known Python Bugs

Python bugs affecting trace output in unexpected way:

http://bugs.python.org/issue15005 (Python 2, Linux only)
  • captured stdout from subprocess call becomes corrupted under a trace function that prints to the screen