pystringtemplate -> pythonPackages.pystringtemplate

and use buildPythonPackage

pkgs/development/python-modules/stringtemplate/default.nix

···
-{stdenv, fetchurl, python, antlr}:
+{stdenv, fetchurl, buildPythonPackage, antlr, isPy3k}:
 
-stdenv.mkDerivation rec {
+buildPythonPackage rec {
   name = "PyStringTemplate-${version}";
   version = "3.2b1";
 
···
     sha256 = "0lbib0l8c1q7i1j610rwcdagymr1idahrql4dkgnm5rzyg2vk3ml";
   };
 
-  propagatedBuildInputs = [python antlr];
+  propagatedBuildInputs = [ antlr ];
 
-  dontBuild = true;
+  disabled = isPy3k;
 
-  installPhase = ''
-    python setup.py install --prefix=$out --install-lib=$(toPythonPath $out) -O1
-  '';
+  # No tests included in archive
+  doCheck = false;
 
   meta = {
     homepage = "http://www.stringtemplate.org/";

pkgs/top-level/all-packages.nix

···
 
   pygmentex = callPackage ../tools/typesetting/pygmentex { };
 
-  pystringtemplate = callPackage ../development/python-modules/stringtemplate { };
-
   pythonIRClib = pythonPackages.pythonIRClib;
 
   pythonSexy = callPackage ../development/python-modules/libsexy { };

pkgs/top-level/python-packages.nix

···
     };
   };
 
+  pystringtemplate = callPackage ../development/python-modules/stringtemplate { };
+
   pillow = buildPythonPackage rec {
     name = "Pillow-3.3.1";