your favorite debugging tool?

[Jean-Michel Pichavant]

Esmail wrote:
> Hi Ben,
>
> Ben Finney wrote:
>>
>> Whenever a simple output statement is too cumbersome for debugging, I
>> take it as a sign that the program is too cumbersome to follow.
>
> I'll have to think about this .. though my gut says this is true :-)
>
That is not always true. When it comes to implement complex tasks, you 
can't always avoid writing complex code. Python does not get your code 
more complex than your algorithm, but it cannot always simplify it.

Ben is right when he says that code can often be written in a more 
simpler manner, but they are some occasions when you have to write 
complex code, that the print debug statement won't be efficient enough 
to sort things out. I personally develop/maintain a full application 
written in python (and quite complex for some parts), using the ipdb 
debugger just saved my hours (days) of headache about some very 
difficult bug to spot
> re your other point about the interactive shell, I agree it's useful, but
> to me still doesn't quite do what a full-fledged debugger can - but 
> perhaps
> that is a reflection of my skill with the shell at this point.
>
> Always more to learn.
>
> Esmail
>

90% of the time, print statements + ipython shell will do the trick. The 
post mortem debugging is also very useful. Execute your  python file in 
ipython, then when it exits upon exception, execute
 >>> import pdb ; pdb.pm()
You can then inspect the symbols easily.

JM