How can you inspect the stack trace of an exception in Python?

Question

When an exception occurs in Python, can you inspect the stack? Can you determine its depth? I've looked at the traceback module, but I can't figure out how to use it.

My goal is to catch any exceptions that occur during the parsing of an eval expression, without catching exceptions thrown by any functions it may have called. Don't berate me for using eval. It wasn't my decision.

Answer 1

You can use the inspect module which has some utility functions for tracing. Have a look at the overview of properties of the frame objects.

Answer 2

traceback is enough - and I suppose that documentation describes it rather good. Simplified example:

import sys
import traceback

try:
    eval('a')
except NameError:
    traceback.print_exc(file=sys.stdout)

Answer 3

In addition to AndiDog's answer about inspect, note that pdb lets you navigate up and down the stack, inspecting locals and such things. The source in the standard library pdb.py could be helpful to you in learning how to do such things.