diff --git a/python/obitools3/obidms/_obidms.pxd b/python/obitools3/obidms/_obidms.pxd
index aaea737..5136277 100644
--- a/python/obitools3/obidms/_obidms.pxd
+++ b/python/obitools3/obidms/_obidms.pxd
@@ -15,13 +15,13 @@ cdef class OBIDMS_column:
     cdef  str                data_type                  # associated property: data_type
     cdef  index_t            nb_elements_per_line       # associated property: nb_elements_per_line
     cdef  list               elements_names             # associated property: elements_names
-
+    cdef  index_t            lines_used                 # associated property: lines_used
+    
     cdef  OBIDMS_column_p*   pointer
     cdef  OBIDMS             dms
     cdef  OBIView            view
     cdef  str                dms_name
         
-    cpdef index_t get_nb_lines_used(self)
     cpdef str     get_creation_date(self)
     cpdef str     get_comments(self)
     cpdef dict    get_references(self)
diff --git a/python/obitools3/obidms/_obidms.pyx b/python/obitools3/obidms/_obidms.pyx
index 2c8355c..27bc065 100644
--- a/python/obitools3/obidms/_obidms.pyx
+++ b/python/obitools3/obidms/_obidms.pyx
@@ -125,10 +125,7 @@ cdef class OBIDMS_column :
         lines_used = (self.pointer)[0].header.lines_used
         for line_nb in range(lines_used):
             yield self.get_line(line_nb)
-    
-    cpdef index_t get_nb_lines_used(self):
-        return (self.pointer)[0].header.lines_used
-        
+                
     cpdef str get_creation_date(self):
         return bytes2str(obi_format_date((self.pointer)[0].header.creation_date))
     
@@ -181,12 +178,17 @@ cdef class OBIDMS_column :
     # original_name property getter
     @property
     def original_name(self):
-        return self.original_name
+        return self.original_name   # TODO go get in header
 
     # version property getter
     @property
     def version(self):
-        return self.version
+        return self.version     # TODO go get in header
+
+    # lines_used property getter
+    @property
+    def lines_used(self):
+        return (self.pointer)[0].header.lines_used
 
     @staticmethod
     cdef object get_subclass_type(OBIDMS_column_p column_p) :