How can I extract local variables from a stack trace?

Question

Suppose I have a function that raises unexpected exceptions, so I wrap it in ipdb:

def boom(x, y):
    try:
        x / y
    except Exception as e:
                 


        

Answer 1

Depending on what you need, there are 2 general best practices.

Just print the variables with minimal code edits

Have a look at some related packages. For simple usage you might pick traceback-with-variables (pip install traceback-with-variables), here is it's postcard

Or try tbvaccine, or better-exceptions, or any other package

Programmatically access variables to use them in your code

Use inspect module

except ... as ...:
    x = inspect.trace()[-1][0].f_locals['x']

What about debugger?

Debugger is made for step-by-step execution and breakpoints. Using it to inspect exception reasons is really inconvenient and should be avoided. You can automate your debug session using two mentioned best practices.