Is it possible to use bpython as a full debugger?

Question

I would like to use the bpython interpreter for debugging. My question is similar to "Is it possible to go into ipython from code?", which asks about ipython.

If you use ipdb.set_trace() you get a full ipython session with all of its conveniences. However, bpdb.set_trace() doesn't give me a bpython session, it gives me the standard pdb debugger.

Is there any way of setting things up so that I can debug within a bpython session?

Soliloquize

Would it cost you a lot to try it? – Sherrod

@Sherrod I should clarify that bpdb.set_trace() gives me the standard pdb debugger – Soliloquize

So, is that a problem? How does a question arise from that? – Sherrod

Yes: If you use ipdb.set_trace() you get a full ipython debugger session with all of its conveniences. In my opinion bpython is much nicer to work with, however bpdb.set_trace() doesn't give me a bpython session – Soliloquize

@MRE Yep, it's doable. See my answer. – Vengeance

Answer 1

Yes, using this wrapper, which you can also access by adding the statement import bpdb to your code. Add bpdb.set_trace() wherever you want to break, and from the pdb interpreter enter "B" to jump into a bpython session with everything from the stack frame:

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import pdb
import bpython

class BPdb(pdb.Pdb):
    """ PDB with BPython support. """

    def __init__(self):
        pdb.Pdb.__init__(self)
        self.rcLines = []
        self.prompt = '(BPdb) '
        self.intro = 'Use "B" to enter bpython, Ctrl-d to exit it.'

    def postloop(self):
        # We only want to show the intro message once.
        self.intro = None
        pdb.Pdb.postloop(self)

    ### cmd.Cmd commands


    def do_Bpython(self, arg):
        bpython.embed(self.curframe.f_locals, ['-i'])


    def help_Bpython(self):
        print "B(python)"
        print
        print ("Invoke the bpython interpreter for this stack frame. To exit "
               "bpython and return to a standard pdb press Ctrl-d")


    ### shortcuts
    do_B = do_Bpython
    help_B = help_Bpython

Your question seems perfectly valid to me!

Vengeance

Hi, thanks for pointing me to this, but this is just a wrapper around pdb. It's included in the bpdb module. When I use it, it just gives me the pdb debugger (i.e. no highlighting, completion, docs, etc). Unless it does something different on your machine? – Soliloquize

@MrE This seems to be the extent provided for bpython, but Amjith is absolutely right. For extending pdb to be pleasant as a debugger, pdb++ is the way to go. :) – Vengeance

on further inspection, aka reading the code above, from the pdb debugger session if you type "B" you jump into a bpython session. So I've marked this as correct. – Soliloquize

@MrE I'm glad both of us here were able to assist you! I do apologize on behalf of my peers for the initial downvotes and terse responses you received. I'm just glad we were able to step in and help. :) – Vengeance

No need to apologise. Hope you don't mind if I added the rest of the info to your answer. Feel free to reword if you like. – Soliloquize

@MrE No worries at all. Thanks for taking the time to explain your problem and help us help you (help us all). – Vengeance

Answer 2

If you are looking for a cooler looking debugger that does completion and syntax highlighting you might want to take a look at pdb++. http://pypi.python.org/pypi/pdbpp/

It's a drop in replacement for pdb. So you can continue to use

 import pdb; pdb.set_trace()

and it'll drop you into the pdb++ prompt.

Worthy

Hey, this is really nice. Not quite as slick as bpython (in interactive mode) but still a big and painless upgrade. – Soliloquize

I agree, the completion isn't quite as awesome as bpython. I like the sticky feature, where the code is shown above and highlights the current line that is being executed. – Worthy

Having pdbpp already installed with python3.7+, you can just call breakpoint builtin and pdbpp debugger will take place – Myalgia