python: openpyxl: support Python 2

This fixes pandas for Python 2 since it depends on openpyxl.

pkgs/development/python-modules/openpyxl/2.nix

@@ -0,0 +1,38 @@
+{ lib
+, buildPythonPackage
+, fetchPypi
+, pytest
+, jdcal
+, et_xmlfile
+, lxml
+}:
+
+buildPythonPackage rec {
+  pname = "openpyxl";
+  version = "2.6.4";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "1d53801678e18d7fe38c116f1ad0c2383a654670c4c8806105b611c92d92f2e3";
+  };
+
+  checkInputs = [ pytest ];
+  propagatedBuildInputs = [ jdcal et_xmlfile lxml ];
+
+  postPatch = ''
+    # LICENSE.rst is missing, and setup.cfg currently doesn't contain anything useful anyway
+    # This should likely be removed in the next update
+    rm setup.cfg
+  '';
+
+  # Tests are not included in archive.
+  # https://bitbucket.org/openpyxl/openpyxl/issues/610
+  doCheck = false;
+
+  meta = {
+    description = "A Python library to read/write Excel 2007 xlsx/xlsm files";
+    homepage = https://openpyxl.readthedocs.org;
+    license = lib.licenses.mit;
+    maintainers = with lib.maintainers; [ lihop sjourdois ];
+  };
+}

pkgs/top-level/python-packages.nix

@@ -4198,7 +4198,10 @@ in {
 
   offtrac = callPackage ../development/python-modules/offtrac { };
 
-  openpyxl = callPackage ../development/python-modules/openpyxl { };
+  openpyxl = if isPy3k then
+    callPackage ../development/python-modules/openpyxl { }
+  else
+    callPackage ../development/python-modules/openpyxl/2.nix { };
 
   opentimestamps = callPackage ../development/python-modules/opentimestamps { };