Add conversion checking on the value of a seq column

python/obitools3/obidms/_obidmscolumn_seq.pyx

@@ -94,10 +94,16 @@ cdef class OBIDMS_column_multi_elts_seq(OBIDMS_column_multi_elts):
 
     cpdef set_item(self, index_t line_nb, str element_name, object value):
         cdef bytes value_b
+        
         if value is None :
             value_b = OBISeq_NA
-        else :
+        elif isinstance(value, bytes) :
+            value_b = value
+        elif isinstance(value, str) :
             value_b = str2bytes(value)
+        else:
+            raise TypeError('Sequence value must be of type Bytes, Str or None')
+        
         if obi_column_set_obiseq_with_elt_name_in_view(self.view.pointer, (self.pointer)[0], line_nb, str2bytes(element_name), value_b) < 0:
             raise Exception("Problem setting a value in a column")