On Wed, Jul 15, 2009 at 9:06 AM, Doug<mcke...@gmail.com> wrote:
>
> This is all awesome info; I've got some reading to do! and I can't
> believe I didn't try reset!
Also, try typing
sage: trace?
William
>
> Thanks! Doug
>
> On Jul 15, 11:30 am, Jason Grout <jason-s...@creativetrax.com> wrote:
>> Doug wrote:
>> > Two more basic questions I'm hoping you can help with:
>>
>> > 1. My workstyle so far is to edit my .sage file in emacs and then load
>> > it into sage on the command line. Sometimes I want my program to stop
>> > in the middle so I can more closely examine/verify what it's doing.
>> > I've been inserting a line that just says "stop" to do this and it
>> > causes sage/Python to stop with an error message and a short stack
>> > trace. This works, but it's kind of messy. "raise Exception
>> > ('spam','eggs')" does pretty much the same thing. Is there a way to
>> > tell sage/Python to stop running without raising an error?
>>
>> One thing you can do is use pdb, the python debugger (example
>> fromhttp://www.electricmonk.nl/log/2008/06/25/breakpoint-induced-python-d...).
>>
>> from IPython.Debugger import Tracer; debug_here = Tracer()
>>
>> def ham():
>> x = 5
>> debug_here()
>> raise NotImplementedError('Use the source, luke!')
>>
>> ham()
>>
>> will put you into the python debugging loop, where you can examine
>> variables, step through the code, etc. Just put these two lines
>> somewhere in your code where you want it to stop. See
>> alsohttp://www.nabble.com/debugging-in-ipython-td20047930.htmlfor another
>> way to set a breakpoint.
>>
>> Another way to enter this is to just turn pdb on in Sage (actually ipython):
>>
>> sage: %pdb on
>>
>> Now any errors will drop you into the debugger.
>>
>> And thirdly, you can just wait until an error shows up and type
>>
>> sage: %debug
>>
>> to examine the variable values, etc. when that error was thrown.
>>
>> Fourthly, you can use pdb to run the function directly:
>>
>> import pdb
>> pdb.run('Networks.FindPathLengthsFromNode(g, 0)')
>>
>> > 2. Is there a way to "reset" sage/Python from the command-line as if I
>> > was restarting? I can't even find a command that will clear all my
>> > global variables, although that might be enough.
>>
>> Check out the (oddly enough named :) reset function:
>>
>> sage: reset?
>>
>> from the reset docs:
>>
>> sage: x = 5
>> sage: reset()
>> sage: x
>> x
>>
>> Thanks,
>>
>> Jason
> >
>
--
William Stein
Associate Professor of Mathematics
University of Washington
http://wstein.org
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