pythonPackages.py3dns: refactor move to python-modules

pkgs/development/python-modules/py3dns/default.nix

@@ -0,0 +1,30 @@
+{ stdenv
+, buildPythonPackage
+, fetchPypi
+}:
+
+buildPythonPackage rec {
+  pname = "py3dns";
+  version = "3.1.1a";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "0z0qmx9j1ivpgg54gqqmh42ljnzxaychc5inz2gbgv0vls765smz";
+  };
+
+  preConfigure = ''
+    sed -i \
+      -e '/import DNS/d' \
+      -e 's/DNS.__version__/"${version}"/g' \
+      setup.py
+  '';
+
+  doCheck = false;
+
+  meta = with stdenv.lib; {
+    description = "Python 3 DNS library";
+    homepage = https://launchpad.net/py3dns;
+    license = licenses.psfl;
+  };
+
+}

pkgs/top-level/python-packages.nix

@@ -3798,25 +3798,7 @@ in {
 
   pydns =
     let
-      py3 = buildPythonPackage rec {
-        name = "${pname}-${version}";
-        pname = "py3dns";
-        version = "3.1.1a";
-
-        src = fetchPypi {
-          inherit pname version;
-          sha256 = "0z0qmx9j1ivpgg54gqqmh42ljnzxaychc5inz2gbgv0vls765smz";
-        };
-
-        preConfigure = ''
-          sed -i \
-            -e '/import DNS/d' \
-            -e 's/DNS.__version__/"${version}"/g' \
-            setup.py
-        '';
-
-        doCheck = false;
-      };
+      py3 = callPackage ../development/python-modules/py3dns { };
 
       py2 = buildPythonPackage rec {
         name = "${pname}-${version}";