Launch an IPython shell on exception

Question

Is there a way to launch an IPython shell or prompt when my program runs a line that raises an exception?

I\'m mostly interested in the context, variables, in the sc

Answer 1

Doing:

ipython --pdb -c "%run exceptionTest.py"

kicks off the script after IPython initialises and you get dropped into the normal IPython+pdb environment.

Answer 2

You can try this:

from ipdb import launch_ipdb_on_exception

def main():
    with launch_ipdb_on_exception():
        # The rest of the code goes here.
        [...]

Answer 3

ipdb integrates IPython features into pdb. I use the following code to throw my apps into the IPython debugger after an unhanded exception.

import sys, ipdb, traceback

def info(type, value, tb):
    traceback.print_exception(type, value, tb)
    ipdb.pm()

sys.excepthook = info

Answer 4

@Adam's works like a charm except that IPython loads a bit slowly(800ms on my machine). Here I have a trick to make the load lazy.

class ExceptionHook:
    instance = None

    def __call__(self, *args, **kwargs):
        if self.instance is None:
            from IPython.core import ultratb
            self.instance = ultratb.FormattedTB(mode='Verbose',
                 color_scheme='Linux', call_pdb=1)
        return self.instance(*args, **kwargs)
sys.excepthook = ExceptionHook()

Now we don't need to wait at the very beginning. Only when the program crashes will cause IPython to be imported.

Answer 5

You can do something like the following:

import sys
from IPython.Shell import IPShellEmbed
ipshell = IPShellEmbed()

def excepthook(type, value, traceback):
    ipshell()

sys.excepthook = excepthook

See sys.excepthook and Embedding IPython.

Answer 6

This man page says iPython has --[no]pdb option to be passed at command line to start iPython for uncaught exceptions. Are you looking for more?

EDIT: python -m pdb pythonscript.py can launch pdb. Not sure about similar thing with iPython though. If you are looking for the stack trace and general post-mortem of the abnormal exit of program, this should work.