simple IO tests

can be improved ...

python/tests/test_Geom.py

@@ -63,6 +63,16 @@ class TestGeom:
             new = Geom.from_file(f)
         assert geom_equal(new,default)
 
+    def test_write_show(self,default,tmpdir):
+        with open(tmpdir.join('str.geom'),'w') as f:
+            f.write(default.show())
+        with open(tmpdir.join('str.geom')) as f:
+            new = Geom.from_file(f)
+        assert geom_equal(new,default)
+
+    def test_export_vtk(self,default,tmpdir):
+        default.to_vtk(str(tmpdir.join('default')))
+
     @pytest.mark.parametrize('pack',[True,False])
     def test_pack(self,default,tmpdir,pack):
         default.to_file(tmpdir.join('default.geom'),pack=pack)