support None, byte arrays, Python numbers as dictionary keys

Author: AlDanial

code/matlab_py/py2mat.m

@@ -45,13 +45,18 @@
         key_index = int64(0);
         for key = cell(py.list(x_py.keys()))
           key_index = key_index + 1;
-          v_name = string(key);
+          if class(key) == 'cell'
+            % key could be a Python number
+            v_name = string(py.str(key{1}));
+          else
+            v_name = string(key);
+          end
           if isvarname(v_name)
             x_mat.(v_name) = x_py.get(v_name);
           else
             % this key can't be used; replace it
             fixed = sprintf('K%06d_', key_index) + ...
-                    regexprep(string(key),'\W','_');
+                    regexprep(v_name,'\W','_');
             x_mat.(fixed) = x_py.get(v_name);
           end
         end
@@ -170,6 +175,12 @@
     case 'logical'
       x_mat = logical(x_py);
 
+    case 'py.bytes'
+      x_mat = uint8(x_py);
+
+    case 'py.NoneType'
+      x_mat = '';
+
     % punt
     otherwise
       % return the original item?  nothing?