diff --git a/python/obitools3/obidms/_obidms.pxd b/python/obitools3/obidms/_obidms.pxd
index 386d672..b0e8312 100644
--- a/python/obitools3/obidms/_obidms.pxd
+++ b/python/obitools3/obidms/_obidms.pxd
@@ -14,7 +14,7 @@ cdef class OBIDMS:
     cdef str dms_name
     
     cpdef dict list(self)
-    
+    cpdef close(self)
     cpdef OBIDMS_column open_column(self,
                                     str column_name,
                                     bint create=*, 
@@ -35,7 +35,7 @@ cdef class OBIDMS_column:
     cdef str column_name
 
     cpdef object get_item(self, size_t line_nb, str element_name)
-#    cpdef        set_item(self, size_t line_nb, str element_name, object value)    TODO
+#    cpdef        set_item(self, size_t line_nb, str element_name, object value)    TODO can't declare because object value
     cpdef list   get_elements_names(self)
     cpdef str    get_data_type(self)
     cpdef size_t get_nb_lines_used(self)
diff --git a/python/obitools3/obidms/_obidms.pyx b/python/obitools3/obidms/_obidms.pyx
index 7c90544..83d4fc7 100644
--- a/python/obitools3/obidms/_obidms.pyx
+++ b/python/obitools3/obidms/_obidms.pyx
@@ -4,7 +4,8 @@ from pathlib import Path
 
 from obitools3.utils cimport bytes2str, str2bytes
 
-from .capi.obidms cimport obi_dms
+from .capi.obidms cimport obi_dms, \
+                          obi_close_dms
 from .capi.obidmscolumn cimport obi_column_get_data_type_from_name, \
                                 obi_column_get_latest_version_from_name, \
                                 obi_column_get_line_count_from_name, \
@@ -51,10 +52,13 @@ cdef class OBIDMS :
         # Fill structure and create or open the DMS
         self.dms_name = dms_name
         self.pointer = obi_dms(<const_char_p> dms_name_b)
+        # TODO: test pointer and raise Exception("Failed opening or creating an OBIDMS")
 
 
-#    def __del__(self) :                        # TODO problem with closing dir breaking everything
-#        obi_close_dms(self.pointer)
+    cpdef close(self) :
+        #TODO close all columns
+        if (obi_close_dms(self.pointer)) < 0 :
+            raise Exception("Problem closing an OBIDMS")
 
 
     cpdef dict list(self):
@@ -121,10 +125,7 @@ cdef class OBIDMS :
             else :
                 data_type = obi_column_get_data_type_from_name(self.pointer, column_name_b)
 
-        # Open the column with the right subclass depending on the data type and the mode (read-only or writable)
-        
-        # TODO : check that data type is the same as previous version if it exists?
-        
+        # Open the column with the right subclass depending on the data type and the mode (read-only or writable)        
         if data_type == 1 :
             if (create or clone) :
                 column = OBIDMS_column_int_writable(self, column_name,