I often have the case that I'll be writing a script, and I'm up to a part of the script where I want to play around with some of the variables interactively. Getting to that part requires running a large part of the script I've already written.
In this case it isn't trivial to run this program from inside the shell. I would have to recreate the conditions of that function somehow.
What I want to do is call a function, like runshell(), which will run the python shell at that point in the program, keeping all variables in scope, allowing me to poke around in it.
How would I go about doing that?
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Are you talking about using the Python debugger? Or are you looking for design advice on how to decompose a large script into more manageable pieces?S.Lott– S.Lott2011年10月06日 16:20:51 +00:00Commented Oct 6, 2011 at 16:20
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i'm asking about the former - i had forgotten that word ('debugger')!Claudiu– Claudiu2011年10月06日 16:49:44 +00:00Commented Oct 6, 2011 at 16:49
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possible duplicate of Jump into a Python Interactive Session mid-program?ljs.dev– ljs.dev2013年10月03日 02:28:33 +00:00Commented Oct 3, 2013 at 2:28
5 Answers 5
import code
code.interact(local=locals())
But using the Python debugger is probably more what you want:
import pdb
pdb.set_trace()
3 Comments
import code; code.interact(local=locals()) thing is perfect for that. Variables and functions defined in that interactive shell are then available when you hit ^D and return to the debugging session. Thanks very much, Michael Hoffman.By far the most convenient method that I have found is:
import IPython
IPython.embed()
You get all your global and local variables and all the creature comforts of IPython: tab completion, auto indenting, etc.
You have to install the IPython module to use it of course:
pip install ipython
1 Comment
For practicality I'd like to add that you can put the debugger trace in a one liner:
import pdb; pdb.set_trace()
Which is a nice line to add to an editor that supports snippets, like TextMate or Vim+SnipMate. I have it set up to expand "break" into the above one liner.
1 Comment
You can use the python debugger (pdb) set_trace function.
For example, if you invoke a script like this:
def whatever():
x = 3
import pdb
pdb.set_trace()
if __name__ == '__main__':
whatever()
You get the scope at the point when set_trace is called:
$ python ~/test/test.py
--Return--
> /home/jterrace/test/test.py(52)whatever()->None
-> pdb.set_trace()
(Pdb) x
3
(Pdb)
Comments
Not exactly a perfect source but I've written a few manhole's before, here is one I wrote for an abandoned pet project http://code.google.com/p/devdave/source/browse/pymethius/trunk/webmud/handlers/konsole.py
And here is one from the Twisted Library http://twistedmatrix.com/trac/browser/tags/releases/twisted-8.1.0/twisted/manhole/telnet.py the console logic is in Shell.doCommand