Start the interactive shell within an application

[Jean-Michel Pichavant]

I was wondering if there is a way to start an interactive shell within a 
script/application.
I'm sometimes tired of adding prints to scan the current namespace so 
I'd like to pause the execution and give the user the shell prompt.
This is obviously for debugging purpose.

I know that I may use the raw_input and eval the  captured text but 
honestly, this requires some coding and I won't benefit from the shell 
features. Would it be even possible to use a shell like Ipython ?

By the way, if anyone has cunning ways for debugging code to share, he 
would be much welcome.

Jean-Michel