diff --git a/python/obitools3/dms/column/column.pyx b/python/obitools3/dms/column/column.pyx
index ea7f6c7..b4a3847 100644
--- a/python/obitools3/dms/column/column.pyx
+++ b/python/obitools3/dms/column/column.pyx
@@ -86,7 +86,7 @@ cdef class Column(OBIWrapper) :
             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,
@@ -129,9 +129,9 @@ cdef class Column(OBIWrapper) :
                 ))
         
         column_p = column_pp[0]
-        column_type = column_p.header.returned_data_type 
+        column_type = column_p.header.returned_data_type
         column_class = Column.get_column_class(column_type, (column_p.header.nb_elements_per_line > 1))
-        column = OBIWrapper.new(column_class, column_pp)
+        column = OBIWrapper.new_wrapper(column_class, column_pp)
         
         column._view = view
         column._alias = column_name_b
@@ -258,8 +258,13 @@ cdef class Column(OBIWrapper) :
     # data_type property getter
     @property
     def data_type(self):
-        return name_data_type(self.pointer().header.returned_data_type)
+        return name_data_type(self.data_type_int)
  
+    # data_type integer code property getter
+    @property
+    def data_type_int(self):
+        return self.pointer().header.returned_data_type
+
     # original_name property getter
     @property
     def original_name(self):
@@ -295,9 +300,13 @@ cdef class Column_multi_elts(Column) :
         return Column_line(self, line_nb)
     
     cpdef set_line(self, index_t line_nb, object values):
-        for element_name in values :
-            self.set_item(line_nb, element_name, values[element_name])
-            
+        if values is None :
+            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])
+
 
 ######################################################################################################
 
@@ -331,6 +340,17 @@ cdef class Column_line :
         elements_names = self._column.elements_names
         for element_name in elements_names :
             yield element_name
+
+
+    # column property getter
+    @property
+    def column(self):
+        return self._column
+
+    # index property getter
+    @property
+    def index(self):
+        return self._index
         
     
     cpdef update(self, data):       # TODO ?????