pythonPackages.mt-940: fix build (#36784)

- added missing `enum34` dependency
- enabled tests
- moved expression into its own file

See ticket #36453
See https://hydra.nixos.org/build/70677609/log

/cc @the-kenny

pkgs/development/python-modules/mt-940/default.nix

@@ -0,0 +1,35 @@
+{ buildPythonPackage, stdenv, pytestrunner, pyyaml, pytest, enum34
+, pytestpep8, pytestflakes,fetchFromGitHub, isPy3k, lib, glibcLocales
+}:
+
+buildPythonPackage rec {
+  version = "v4.10.0";
+  pname = "mt940";
+
+  src = fetchFromGitHub {
+    owner = "WoLpH";
+    repo = pname;
+    rev = version;
+    sha256 = "1dsf2di8rr0iw2vaz6dppalby3y7i8x2bl0qjqvaiqacjxxvwj65";
+  };
+
+  patches = [
+    ./no-coverage.patch
+  ];
+
+  propagatedBuildInputs = [ pyyaml pytestrunner ]
+    ++ lib.optional (!isPy3k) enum34;
+
+  LC_ALL="en_US.UTF-8";
+
+  checkInputs = [ pytestpep8 pytestflakes pytest glibcLocales ];
+  checkPhase = ''
+    py.test
+  '';
+
+  meta = with stdenv.lib; {
+    description = "A library to parse MT940 files and returns smart Python collections for statistics and manipulation";
+    homepage = "http://pythonhosted.org/mt-940/";
+    license = licenses.bsd3;
+  };
+}