pythonPackages.marshmallow-polyfield: init at 5.7

This python package allows polymorphic data fields in marshmallow
serialization/deserialization schema.

This is a requirement for qiskit.

pkgs/development/python-modules/marshmallow-polyfield/default.nix

@@ -0,0 +1,34 @@
+{ buildPythonPackage
+, fetchFromGitHub
+, lib
+, marshmallow
+  # Check Inputs
+, pytestCheckHook
+, pytestcov
+}:
+
+buildPythonPackage rec {
+  pname = "marshmallow-polyfield";
+  version = "5.7";
+
+  src = fetchFromGitHub {
+    owner = "Bachmann1234";
+    repo = pname;
+    rev = "v${version}";
+    sha256 = "15yx8ib5yx1xx6kq8wnfdmv9zm43k7y33c6zpq5rba6a30v4lcnd";
+  };
+
+  propagatedBuildInputs = [
+    marshmallow
+  ];
+  
+  # setuptools check can run, but won't find tests
+  checkInputs = [ pytestCheckHook pytestcov ];
+
+  meta = with lib; {
+    description = "An unofficial extension to Marshmallow to allow for polymorphic fields";
+    homepage = "https://github.com/Bachmann1234/marshmallow-polyfield";
+    license = licenses.asl20;
+    maintainers = with maintainers; [ drewrisinger ];
+  };
+}

pkgs/top-level/python-packages.nix

@@ -4158,6 +4158,8 @@ in {
 
   marshmallow-enum = callPackage ../development/python-modules/marshmallow-enum { };
 
+  marshmallow-polyfield = callPackage ../development/python-modules/marshmallow-polyfield { };
+
   marshmallow-sqlalchemy = callPackage ../development/python-modules/marshmallow-sqlalchemy { };
 
   manuel = callPackage ../development/python-modules/manuel { };