[Openmcl-devel] access Mac OS python interpreter from clozure?

[Gary Byers]

On 10/01/2014 05:15:02 PM, Mark Klein wrote:
> 
> To add more detail to my previous question, I wonder if I can do  
> something like the following:
> 
> (defun test ()
>   (setq p (run-program "python" nil
>                        :wait t

In general, if you want to "interact" with the external-proceess  
(rather than wait for it to complete) it's preferable to say :WAIT NIL  
here.  (You likely got past this point, if you discovered that reading  
the process's output likely hangs.)

>                        :input :stream
>                        :output :stream))
>   (setq is (external-process-input-stream p))
>   (setq os (external-process-output-stream p))
>   (loop do (format is "~A~%"  (read-line))
>            do (format t "~%~A" (read-line os))))
> 
> The idea is that this would create a process running python and allow  
> me to send and receive text to it. The code above doesn’t work, the  
> read from the external process output stream never returns, but  
> perhaps there’s a simple fix?

As Jeff Caldwell suggested, the output that the Python interpreter  
generates seems to be buffered on the Python side.  Starting Python  
with the "-i" option seens to defeat this buffering but also seems to  
cause it to print ">>>" prompts which aren't terminated by newlines  
after any other generated output.  (I guess that it can also generate  
"..."
prompts in some cases.)  Reading the output generated by another  
process may be somewhat harder than just calling READ-LINE, and AFAICT  
Python's "-i" option can make it complicated in cases where it  
otherwise wouldn't be.

> 
>     Thanks,
> 
> Mark
> 
> 
> Hi,
> 
> I’d like to create input and output streams that connect with the  
> python interpreter that comes included with Mac OS X so I can invoke  
> python subroutines from lisp and get the results. Does anyone have  
> any suggestions about how that can be done? I see that Clozure allows  
> running other programs as subprocesses  
> (http://ccl.clozure.com/ccl-documentation.html#Running-Other-Programs-as-Subprocesses)  
> but it’s not clear to me if I can use that to interact with a program  
> like python, as oppose to simply invoking a program like “cat” and  
> getting the results it returns when it completes.
> 
> Thanks for your help!
> 
> Mark
> 
> -------------------------------
> Mark Klein
> http://cci.mit.edu/klein
> 
> Principal Research Scientist
> Center for Collective Intelligence
> Massachusetts Institute of Technology
> 
> Visiting Researcher
> Dynamic and Distributed Information Systems Group
> University of Zurich
> 
> 
> -------------------------------
> Mark Klein
> http://cci.mit.edu/klein
> 
> Principal Research Scientist
> Center for Collective Intelligence
> Massachusetts Institute of Technology
> 
> Visiting Researcher
> Dynamic and Distributed Information Systems Group
> University of Zurich
> 
> 

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