Step-by-step debugging with IPython

Question

From what I have read, there are two ways to debug code in Python:

• With a traditional debugger such as pdb or ipdb. This supports c

Answer 1

You can start IPython from within ipdb!

Induce the ipdb debugger¹:

import idpb; ipdb.set_trace()

Enter IPython from within in the ipdb> console²:

from IPython import embed; embed()

Return to the ipdb> console from within IPython:

exit

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If you're lucky enough to be using Emacs, things can be made even more convenient!

This requires using M-x shell. Using yasnippet and bm, define the following snippet. This will replace the text ipdb in the editor with the set-trace line. After inserting the snippet, the line will be highlighted so that it is easily noticeable and navigable. Use M-x bm-next to navigate.

# -*- mode: snippet -*-
# name: ipdb
# key: ipdb
# expand-env: ((yas-after-exit-snippet-hook #'bm-toggle))
# --
import ipdb; ipdb.set_trace()

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¹ All on one line for easy deletion. Since imports only happen once, this form ensures ipdb will be imported when you need it with no extra overhead.

² You can save yourself some typing by importing IPython within your .pdbrc file:

try:
    from IPython import embed
except:
    pass

This allows you to simply call embed() from within ipdb (of course, only when IPython is installed).