Fix utf-8 encoding in doxy2swig.py

src/.doxy2swig.py

@@ -378,18 +378,18 @@ def do_doxygenindex(self, node):
             if not os.path.exists(fname):
                 fname = os.path.join(self.my_dir,  fname)
             if not self.quiet:
-                print ("parsing file: %s", fname)
+                print("parsing file: %s", fname)
             p = Doxy2SWIG(fname, self.include_function_definition, self.quiet)
             p.generate()
             self.pieces.extend(self.clean_pieces(p.pieces))
 
     def write(self, fname):
         o = my_open_write(fname)
-        if self.multi:
-            o.write("".join(self.pieces))
-        else:
-            o.write("".join(self.clean_pieces(self.pieces)))
-        o.close()
+        try:
+            data = self.pieces if self.multi else self.clean_pieces(self.pieces)
+            o.write(str("".join(data).encode("UTF-8")))
+        finally:
+            o.close()
 
     def clean_pieces(self, pieces):
         """Cleans the list of strings given as `pieces`.  It replaces