Michael Steeves <steeves@raingods.net> writes:

> On 6/6/13 12:04 PM, Eric Schulte wrote:
>> Michael Steeves <steeves@raingods.net> writes:
>>> Is there any way to suppress all the extra text, and just get the
>>> "Hello, world." string as my output?
>>>
>> 
>> #+begin_src python :session testing
>> a = 1
>> b = 2
>> c = a + b
>> "Hello, world."
>> #+end_src
>> 
>> #+RESULTS:
>> : Hello, world.
>
> Thanks for the reply. Unfortunately I need to set :results to output,
> since I'm working with a doc where I'm working through a python script,
> and want to run a section, get some output and write some additional
> text, then move on to the next block (and all within a session, since
> block 2 depends on things from block 1, and so on.
>
> I put together a more descriptive example, but interestingly enough I'm
> now getting some inconsistent output when I evaluate the source blocks.
>
> #+BEGIN_SRC python :session testing :results output
> print "Hello, World."
> print "This is a test."
> #+END_SRC
>
> #+RESULTS:
> : Hello, World.
> : This is a test.
>
> #+BEGIN_SRC python :session testing :results output
> a = 1; b = 2
> print "A is "+str(a)
> print "B is "+str(b)
> #+END_SRC
>
> #+RESULTS:
> :
> : A is 1
> : B is 2
>
> #+BEGIN_SRC python :session testing :results output
> c = a + b
> print "C is "+str(c)
> print "Now we're done."
> #+END_SRC
>
> #+RESULTS:
> :
> : C is 3
> : Now we're done.
>
> #+BEGIN_SRC python :session testing :results output
> y = 3
> z = 4
> print "Y is "+str(y)
> print "Z is "+str(z)
> #+END_SRC
>
> #+RESULTS:
> :
> : >>> Y is 3
> : Z is 4
>
> I don't understand why the last chunk provides different output than the
> second -- the only real difference is that I put the assignments on one
> line (seperated with a semicolon) in the second, and on individual lines
> in the last.
>

The cleaning of prompts is a best effort based on things like the prompt
regexp variable in the python session comint buffer.  As it interacts
with an external process it can be somewhat noisy, seemingly especially
so with python sessions.

The attached version of your example file uses a simple post processor
to automatically clean up anything that looks like python session cruft
after each code block execution.