How to execute multi-line statements within Python's own debugger (PDB)

You could do this while in pdb to launch a temporary interactive Python session with all the local variables available:

(pdb) !import code; code.interact(local=vars())
Python 2.6.5 (r265:79063, Apr 16 2010, 13:57:41) 
[GCC 4.4.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> 

When you're done, use Ctrl-D to return to the regular pdb prompt.

Just don't hit Ctrl-C, that will terminate the entire pdb session.

In python3 ipdb (and pdb) have a command called interact. It can be used to:

Start an interactive interpreter (using the code module) whose global namespace contains all the (global and local) names found in the current scope.

To use it, simply enter interact at the pdb prompt. Among other things, it's useful for applying code spanning multiple lines, and also for avoiding accidental triggering of other pdb commands.

My recommendation is to use IPython embedding.

ipdb> from IPython import embed; embed()