Stepping into a function in IPython

Question

Is there a way to step into the first line of a function in ipython. I imagine something that would look like:

%step foo(1, 2)

which runs ipdb and sets a breakpoint at the first line of foo.

If I want to do this now I have to go to the function's source code and add an import ipdb; ipdb.set_trace() line.

There's no function like %step. You can %run -d a whole script, but you can't do the same thing for a single statement or function call. You can manually pdb.run("foo(1, 2)") or pdb.runcall(foo, 1, 2). — abarnert
– abarnert, Commented Sep 28, 2012 at 20:21
I was just wondering the same thing today. I would use this all the time if it was available. Time to dig into the iPython source to see how it could be implemented. — Daniel Roseman
– Daniel Roseman, Commented Sep 28, 2012 at 20:22
Possible duplicate of Is it possible to run commands in IPython with debugging? — ivan_pozdeev
– ivan_pozdeev, Commented Sep 20, 2017 at 19:09

Ian Clelland · Accepted Answer · 2012-09-28 20:36:32Z

67

ipdb has had support for runcall, runeval and run since 0.7, earlier this year. You can use it just like pdb.runcall:

In [1]: def foo(a, b):
   ...:     print a + b
   ...:

In [2]: import ipdb

In [3]: ipdb.runcall(foo, 1, 2)
> <ipython-input-1-2e565fd9c4a4>(2)foo()
      1 def foo(a, b):
----> 2     print a + b
      3

ipdb>

answered Sep 28, 2012 at 20:36

Ian Clelland

44.4k8 gold badges90 silver badges88 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Daniel Over a year ago

That's pretty much what I need. Thanks for pointing out the 0.7 update, I had an older version. Having that it's probably easy to add an ipython magic which uses runcall.

Daniel Roseman Over a year ago

Actually it turns out you don't need the external ipdb, you can just do from IPython.core.debugger import Pdb; ipdb=Pdb().

ivan_pozdeev Over a year ago

Not the most elegant method. I expected a magic function for such a common need. I wonder if it's not a common need for SciPy users...

Jean Paul · Accepted Answer · 2018-09-28 12:38:00Z

46

The IPython magic you was asking for is now implemented with the newer versions: https://stackoverflow.com/a/46333421/4374441

You just have to type %debug foo(1, 2) then s to step into the function.

answered Sep 28, 2018 at 12:38

Jean Paul

1,6281 gold badge19 silver badges24 bronze badges

1 Comment

El'endia Starman Over a year ago

Six years later to the day from the original answer! +1 works for me.

Collectives™ on Stack Overflow

Stepping into a function in IPython

2 Answers 2

3 Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related