anchor.diff:    inherit (stdenv.lib)
       optionals;
     inherit (pythonPackages)
  +    isPy3k
       pythonOlder;
   in
   
  
positive.code: { stdenv
  , buildPythonPackage
  , config
  , fetchurl
  
  , pythonPackages
  }:
  
  
negative.code:     pythonPackages.jinja2
      pythonPackages.jsonschema
      pythonPackages.pathpy
      #pythonPackages.progressbar
      pythonPackages.pynzb
      pythonPackages.pyparsing
      pythonPackages.pyrss2gen
      pythonPackages.python-dateutil
      pythonPackages.pyyaml
      pythonPackages.requests2
      pythonPackages.rpyc
      pythonPackages.safe
      pythonPackages.sqlalchemy
  
      #pythonPackages.paver
      #pythonPackages.python-tvrage
      #pythonPackages.tmdb3
      pythonPackages.transmissionrpc
    ] ++ optionals (pythonOlder "3.4") [
      pythonPackages.pathlib
  