anchor.diff:  { pkgs, python }:
  -  with pkgs.lib;
  +
  +with pkgs.lib;
   
   let
     isPy26 = python.majorVersion == "2.6";
  
positive.code:     if isPy34 then "python34" else
      if isPyPy then "pypy" else "";
  
    modules = python.modules or { readline = null; sqlite3 = null; curses = null; curses_panel = null; ssl = null; crypt = null; };
  
  pythonPackages = modules // import ./python-packages-generated.nix {
    inherit pkgs python;
    inherit (pkgs) stdenv fetchurl;
    self = pythonPackages;
  } //
  
  # Python packages for all python versions
  rec {
  
    inherit python isPy26 isPy27 isPy33 isPy34 isPyPy isPy3k pythonName;
    inherit (pkgs) fetchurl fetchsvn fetchgit stdenv unzip;
  
    # helpers
  
    callPackage = callPackageWith (pkgs // pythonPackages);
  
    # global distutils config used by buildPythonPackage
    distutils-cfg = callPackage ../development/python-modules/distutils-cfg { };
  
negative.code: 
  
  
  }); in pythonPackages