anchor.diff:        description = "Powerful extensions to the standard datetime module";
         homepage = http://pypi.python.org/pypi/python-dateutil;
         license = "BSD-style";
  +    };
  +  });
  +
  +  dateutil_2_1 = buildPythonPackage (rec {
  +    name = "dateutil-2.1";
  +
  +    src = fetchurl {
  +      url = "http://pypi.python.org/packages/source/p/python-dateutil/python-${name}.tar.gz";
  +      sha256 = "1vlx0lpsxjxz64pz87csx800cwfqznjyr2y7nk3vhmzhkwzyqi2c";
  +    };
  +
  +    propagatedBuildInputs = [ pythonPackages.six ];
  +
  +    meta = {
  +      description = "Powerful extensions to the standard datetime module";
  +      homepage = http://pypi.python.org/pypi/python-dateutil;
  +      license = stdenv.lib.licenses.bsd3;
       };
     });
   
  
positive.code:   };
  
    flexget = buildPythonPackage rec {
      name = "FlexGet-1.2.161";
      disabled = isPy3k;
  
      src = pkgs.fetchurl {
        url = "https://pypi.python.org/packages/source/F/FlexGet/${name}.tar.gz";
        md5 = "f7533e7b1df49cc8027fc4a2cde0290d";
      };
  
      buildInputs = with self; [ nose ];
      # dateutil dependency: requirement is dateutil !=2.0 and != 2.2,
      # dateutil_1_5 is used as it's supported, but a newer version could be used
      propagatedBuildInputs = with self; [ paver feedparser sqlalchemy pyyaml rpyc
  	    beautifulsoup4 html5lib pyrss2gen pynzb progressbar jinja2 flask
  	    cherrypy requests dateutil_1_5 jsonschema python_tvrage tmdb3 ]
  	# enable deluge and transmission plugin support, if they're installed
  	++ stdenv.lib.optional (pkgs.config.pythonPackages.deluge or false)
  	    pythonpackages.deluge
  
negative.code:     };
    };
  
    babelfish = buildPythonPackage rec {
      version = "0.5.3";
      name = "babelfish-${version}";
  
      src = fetchurl {
        url = "https://pypi.python.org/packages/source/b/babelfish/${name}.tar.gz";
        sha256 = "0wrw21dyq7v6lbffwvi1ik43d7dhmcv8xvgrrihhiv7ys1rd3gag";
      };
  
      meta = {
        homepage = http://pypi.python.org/pypi/babelfish;
        description = "A module to work with countries and languages.";
        license = stdenv.lib.licenses.bsd3;
      };
    };
  
    batinfo = buildPythonPackage rec {
      version = "0.1.9";
      name = "batinfo-${version}";
  