How do you see the return value from a function in the Python debugger, without an intermediate?

Question

PDB (and other Python debuggers) have a simple way of viewing the value of any current variable, just by typing it in. However, sometimes I work with libraries that don\'t store

Answer 1

You can look into a hidden __return__ local variable.

If I would forget it's exact name, I explore it by this:

(Pdb) sorted(locals().keys())
['__return__', 'xyz', ...]

EDIT: Related later answer with example of debugging with __return__

Answer 2

In pdb, when the function returns a ->'value' is added at the end of the line with the representation of the returned value.

For example:

(Pdb) s
--Return--
> test.py(12)do_stuff()->'f'
-> return result
(Pdb) q

means do_stuff() returned 'f'

Answer 3

Can you explain more?

• By debugger, do you mean you are using a logger? Are you stepping through with an IDE?

• What do you mean by "see the return value"? If you just want to print it...

  def do_stuff(*args, **kwds):
      result = f(*args, **kwds)
      print result
      return result