Skip to main content
Join the official Python Developers Survey 2018 and win valuable prizes: Start the survey!

nice Python exception hook replacement

Project description

==============
better_exchook
==============

A nicer drop-in-replacement for Python ``sys.excepthook``.
It will add some useful information for each frame,
like printing the relevant variables (relevant = referenced in the code line).
Also see `Python source and comments <https://github.com/albertz/py_better_exchook/blob/master/better_exchook.py>`_ for further details.

You can just copy over the file ``better_exchook.py`` to your project.
Or alternatively, it is also available `on PyPI <https://pypi.python.org/pypi/better_exchook>`_
and can be installed via:

.. code::

pip install better_exchook

Usage:

.. code:: python

import better_exchook
better_exchook.install() # will just do: sys.excepthook = better_exchook

Python example code:

.. code:: python

try:
x = {1:2, "a":"b"}
def f():
y = "foo"
x, 42, sys.stdin.__class__, sys.exc_info, y, z
f()
except Exception:
better_exchook.better_exchook(*sys.exc_info())

Output:

.. code::

EXCEPTION
Traceback (most recent call last):
File "better_exchook.py", line 478, in <module>
line: f()
locals:
f = <local> <function f at 0x107f1de60>
File "better_exchook.py", line 477, in f
line: x, 42, sys.stdin.__class__, sys.exc_info, y, z
locals:
x = <global> {'a': 'b', 1: 2}
sys = <global> <module 'sys' (built-in)>
sys.stdin = <global> <open file '<stdin>', mode 'r' at 0x107d9f0c0>
sys.stdin.__class__ = <global> <type 'file'>
sys.exc_info = <global> <built-in function exc_info>
y = <local> 'foo'
z = <not found>
NameError: global name 'z' is not defined

Python example code:

.. code:: python

try:
f = lambda x: None
f(x, y)
except Exception:
better_exchook.better_exchook(*sys.exc_info())

Output:

.. code::

EXCEPTION
Traceback (most recent call last):
File "better_exchook.py", line 484, in <module>
line: f(x, y)
locals:
f = <local> <function <lambda> at 0x107f1df50>
x = <local> {'a': 'b', 1: 2}
y = <not found>
NameError: name 'y' is not defined

Python example code:

.. code:: python

try:
(lambda x: None)(__name__,
42) # multiline
except Exception:
better_exchook.better_exchook(*sys.exc_info())

Output:

.. code::

EXCEPTION
Traceback (most recent call last):
File "better_exchook.py", line 490, in <module>
line: (lambda x: None)(__name__,
42) # multiline
locals:
x = <local> {'a': 'b', 1: 2}
__name__ = <local> '__main__', len = 8
TypeError: <lambda>() takes exactly 1 argument (2 given)

Python example code:

.. code:: python

# use this to overwrite the global exception handler
sys.excepthook = better_exchook.better_exchook
# and fail
finalfail(sys)

Output:

.. code::

EXCEPTION
Traceback (most recent call last):
File "better_exchook.py", line 497, in <module>
line: finalfail(sys)
locals:
finalfail = <not found>
sys = <local> <module 'sys' (built-in)>
NameError: name 'finalfail' is not defined


Similar projects:
- `<https://github.com/patrys/great-justice>`_
- `Nose does something similar for assertion failures <http://nose.readthedocs.io/en/latest/plugins/failuredetail.html>`_.
- IPython has something similar (`this <https://github.com/ipython/ipython/blob/master/IPython/core/ultratb.py>`_). Do this: ``from IPython.core import ultratb; sys.excepthook = ultratb.VerboseTB()``.
- Ka-Ping Yee's "cgitb.py", which is part of Python, `see here <https://docs.python.org/3/library/cgitb.html>`_, `code here <https://github.com/python/cpython/blob/3.7/Lib/cgitb.py>`_.
- See `this <http://stackoverflow.com/questions/1308607/python-assert-improved-introspection-of-failure>`_ related StackOverflow question.


-- Albert Zeyer, <http://www.az2000.de>

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Filename, size & hash SHA256 hash help File type Python version Upload date
better_exchook-1.20181019.221648.tar.gz (14.9 kB) Copy SHA256 hash SHA256 Source None Oct 19, 2018

Supported by

Elastic Elastic Search Pingdom Pingdom Monitoring Google Google BigQuery Sentry Sentry Error logging AWS AWS Cloud computing DataDog DataDog Monitoring Fastly Fastly CDN SignalFx SignalFx Supporter DigiCert DigiCert EV certificate StatusPage StatusPage Status page