diff --git a/python/obitools3/obidms/_obidms.pyx b/python/obitools3/obidms/_obidms.pyx
index c35cd14..7f86c59 100644
--- a/python/obitools3/obidms/_obidms.pyx
+++ b/python/obitools3/obidms/_obidms.pyx
@@ -100,17 +100,17 @@ cdef class OBIDMS_column :
     def __getitem__(self, index_t line_nb):
         return self.get_line(line_nb)
 
-    def __len__(self):
-        return self.lines_used
+    def __len__(self):        # TODO discuss
+        return self._view.line_count
     
     def __sizeof__(self):
         return ((self._pointer)[0].header.header_size + (self._pointer)[0].header.data_size)
     
-    def __iter__(self):
+    def __iter__(self):      # TODO discuss
         # Declarations
         cdef index_t line_nb  
         # Yield each line
-        for line_nb in range(self.lines_used):
+        for line_nb in range(self._view.line_count): 
             yield self.get_line(line_nb)
                 
     def __str__(self) :
@@ -160,11 +160,6 @@ cdef class OBIDMS_column :
     def version(self):
         return ((self._pointer)[0].header).version
 
-    # lines_used property getter
-    @property
-    def lines_used(self):
-        return (self._pointer)[0].header.lines_used
-
     # comments property getter
     @property
     def comments(self):