Open interactive shell to investigate when something throws an exception

python-commandline-if-exception.py

try:
    # this is what fails here
    context['children'] = mark_safe(u''.join(parts))
except:
    import code
    import readline
    import rlcompleter
    vars = globals()
    vars.update(locals())
    readline.set_completer(rlcompleter.Completer(vars).complete)
    readline.parse_and_bind("tab: complete")
    shell = code.InteractiveConsole(vars)
    shell.interact()

# OR, w/ IPython:

from IPython import embed
embed() # this call anywhere in your program will start IPython