Python pdb (debugger) disp equivalent?

Question

Is there a pdb equivalent to disp in gdb?

E.g. when I'm debugging C using gdb I can have variables printed on every 'step' through the code by typing:

disp var

When I'm debugging python using pdb I would like similar functionality, but disp does not seem to be there, the python pdb documentation does not seem to offer an alternative - but it seems like an odd omission?

Answer 1

During the pdb debugging you can type normal python code, beyond the one letter commands - so just using print var should work for you.

Answer 2

You can set up some aliases that will do this for you:

alias n next;; p var
alias s step;; p var

Printing a whole list of variable names is left as an exercise to the reader. Unfortunately doing it this way means that when you send the debugger an empty line, the "last command" it executes is p var rather than, for example, n. If you want to fix that, then you can use this somewhat hacky set of Pdb commands instead:

!global __stack; from inspect import stack as __stack
!global __Pdb; from pdb import Pdb as __Pdb
!global __pdb; __pdb = [__framerec[0].f_locals.get("pdb") or __framerec[0].f_locals.get("self") for __framerec in __stack() if (__framerec[0].f_locals.get("pdb") or __framerec[0].f_locals.get("self")).__class__ == __Pdb][-1]

alias s step;; p var;; !__pdb.lastcmd = "!__pdb.cmdqueue.append('s')"
alias n next;; p var;; !__pdb.lastcmd = "!__pdb.cmdqueue.append('n')"