diff --git a/python/obitools3/dms/column/column.pxd b/python/obitools3/dms/column/column.pxd
index eb2be52..81ef1f7 100644
--- a/python/obitools3/dms/column/column.pxd
+++ b/python/obitools3/dms/column/column.pxd
@@ -39,7 +39,7 @@ cdef class Column_line:
     cdef Column    _column
     cdef index_t   _index
 
-    cpdef update(self, data)
+    cpdef update(self, object data)
      
     
 cdef register_column_class(obitype_t obitype,
diff --git a/python/obitools3/dms/column/column.pyx b/python/obitools3/dms/column/column.pyx
index 65f37a3..e59a6bc 100644
--- a/python/obitools3/dms/column/column.pyx
+++ b/python/obitools3/dms/column/column.pyx
@@ -80,24 +80,33 @@ cdef class Column(OBIWrapper) :
                    object    alias=b""):
         # TODO indexer_name?
         
-        cdef bytes column_name_b = tobytes(column_name)
-        cdef bytes alias_b = tobytes(alias)
-        cdef bytes comments_b = tobytes(comments)
-        cdef bytes elements_names_b
-        cdef char* elements_names_p
-
+        cdef bytes  column_name_b = tobytes(column_name)
+        cdef bytes  alias_b = tobytes(alias)
+        cdef bytes  comments_b = tobytes(comments)
+        cdef list   elements_names_s
+        cdef bytes  elements_names_b
+        cdef char*  elements_names_p
+        cdef object elt_name
+        cdef str    elt_name_s
+        
         if not view.active() :
             raise OBIDeactivatedInstanceError()
  
         if alias_b == b"" :
             alias_b = column_name_b
- 
+        
         if elements_names is not None:
-            elements_names_b = b';'.join([tobytes(x) for x in elements_names])
+            elements_names_s = []
+            for elt_name in elements_names :
+                if type(elt_name) != bytes and type(elt_name) != str :
+                    elements_names_s.append(str(elt_name))
+                else :
+                    elements_names_s.append(elt_name)
+            elements_names_b = b';'.join([tobytes(x) for x in elements_names_s])
             elements_names_p = elements_names_b
         else:
             elements_names_p = NULL
-                    
+        
         if (obi_view_add_column(view                      = view.pointer(),
                                 column_name               = column_name_b,
                                 version_number            = -1,
@@ -342,15 +351,17 @@ cdef class Column_multi_elts(Column) :
         return Column_line(self, line_nb)
     
     cpdef set_line(self, index_t line_nb, object values):
-        cdef object element_name
+        cdef object value_ref
+        cdef object values_iter
         if not self.active() :
             raise OBIDeactivatedInstanceError()
-        if values is None :
+        if values is None or len(values) == 0 :
             for element_name in self.elements_names :
                 self.set_item(line_nb, element_name, None)
         else :
-            for element_name in values :
-                self.set_item(line_nb, element_name, values[element_name])
+            values_iter = xrange(len(values)) if isinstance(values, list) else values
+            for value_ref in values_iter :
+                self.set_item(line_nb, value_ref, values[value_ref])
 
 
 ######################################################################################################
@@ -395,7 +406,11 @@ cdef class Column_line :
         elements_names = self._column.elements_names
         for element_name in elements_names :
             yield element_name
-
+    
+    
+    def keys(self):    # TODO Discuss if keys with None values should be returned too
+        return self._column.elements_names
+    
 
     # column property getter
     @property
@@ -408,7 +423,7 @@ cdef class Column_line :
         return self._index
         
     
-    cpdef update(self, data):       # TODO ?????
+    cpdef update(self, object data):
         if isinstance(data, dict):
             data=data.items()
         for key,value in data: