Making the case for "typed" lists/iterators in python

[Roy Smith]

In article <mailman.3739.1324057724.27778.python-list at python.org>,
 Nathan Rice <nathan.alexander.rice at gmail.com> wrote:

> I'd like to hear people's thoughts on the subject.  Currently we are
> throwing away useful information in many cases that could be used for
> code analysis, optimization and simpler interfaces. 

Most of this was TL:DNR, but I will admit I often wish for a better way 
to log intermediate values.  For example, a common pattern in the code 
I'm working with now is functions that end in:

   return [Foo(x) for x in bunch_of_x_thingies]

When something goes amiss and I want to debug the problem, I often 
transform that into:

    temp = [Foo(x) for x in bunch_of_x_thingies]
    logger.debug(temp)
    return temp

It would be convenient to be able to get at and log the intermediate 
value without having to pull it out to an explicit temporary.