pipes.py and its limits

[val]

Hi All,
   i'm looking at pipes.py, a great pipeline implementation
   in python (BTW, who is the author?), and trying to figure
   out its limits.  The description says that the commands
   to be appended to the pipeline template have to be
   shell functions.  I'd like to try to build the dynamic pipelines
   using the python functions or callable objects.

   In other words, i'd like to modify the pipeline -
   its functional components on-the-fly depending on
   the results of running the pipeline (its output).

   I'm sure the real Pythoneers know how to do that.
   Any pointers/help would be highly appreciated.

thanx,
val