anchor.diff:    odo = buildPythonPackage rec {
       name = "odo-${version}";
       version= "0.3.3";
  -    
  +
       src = pkgs.fetchurl {
         url = "https://pypi.python.org/packages/source/o/odo/${name}.tar.gz";
         sha256 = "2499ee86c26c74daa28f21ed235ca331911065950deea5169ebdb7d5dae6ebef";
       };
  -    
  +
       propagatedBuildInputs = with self; [ datashape numpy pandas toolz multipledispatch networkx ];
  -    
  +
       meta = {
         homepage = https://github.com/ContinuumIO/odo;
         description = "Data migration utilities";
         license = licenses.bsdOriginal;
       };
     };
  -  
  +
     offtrac = buildPythonPackage rec {
       name = "offtrac-0.1.0";
       meta.maintainers = with maintainers; [ mornfall ];
  
positive.code:   multipledispatch = buildPythonPackage rec {
      name = "multipledispatch-${version}";
      version = "0.4.8";
     
      src = pkgs.fetchurl {
        url = "https://pypi.python.org/packages/source/m/multipledispatch/${name}.tar.gz";
        sha256 = "07d41fb3ed25e8424536e48a8566f88a0f9926ca4b6174bff6aa16c98251b92e";
      };
      
      meta = {
        homepage = http://github.com/mrocklin/multipledispatch/;
        description = "A relatively sane approach to multiple dispatch in Python";
  
negative.code:   terminado = buildPythonPackage rec {
      name = "terminado-${version}";
      version = "0.5";
  
      src = pkgs.fetchurl {
        url = "https://pypi.python.org/packages/source/t/terminado/${name}.tar.gz";
        sha256 = "63e893eff1ba84f1ee7c4bfcca7676ba1de6394538bb9aa80cbbc8866cb875b6";
      };
  
      propagatedBuildInputs = with self; [ ptyprocess tornado ];
  
      meta = {
        description = "Terminals served to term.js using Tornado websockets";
        homepage = https://github.com/takluyver/terminado;
        licenses = licenses.bsd2;
      };
    };
  
    testscenarios = buildPythonPackage rec {
      name = "testscenarios-${version}";
      version = "0.4";
  