diff --git a/python/obitools3/dms/obiseq.pyx b/python/obitools3/dms/obiseq.pyx
index 3b8aa74..b92073c 100644
--- a/python/obitools3/dms/obiseq.pyx
+++ b/python/obitools3/dms/obiseq.pyx
@@ -3,9 +3,15 @@
 from obitools3.utils cimport bytes2str, str2bytes
 
 from .capi.obiview cimport NUC_SEQUENCE_COLUMN, \
-                            ID_COLUMN, \
-                            DEFINITION_COLUMN, \
-                            QUALITY_COLUMN
+                           ID_COLUMN, \
+                           DEFINITION_COLUMN, \
+                           QUALITY_COLUMN
+
+
+NUC_SEQUENCE_COLUMN_str = bytes2str(NUC_SEQUENCE_COLUMN)
+ID_COLUMN_str           = bytes2str(ID_COLUMN)
+DEFINITION_COLUMN_str   = bytes2str(DEFINITION_COLUMN)
+QUALITY_COLUMN_str      = bytes2str(QUALITY_COLUMN)
 
 
 cdef class Seq(dict) :
@@ -23,7 +29,7 @@ cdef class Seq(dict) :
     @id.setter
     def id(self, str new_id):  # @ReservedAssignment @DuplicatedSignature
         self._id = new_id
-        self[bytes2str(ID_COLUMN)] = new_id
+        self[ID_COLUMN] = new_id
         
     # sequence property getter and setter
     @property
@@ -43,7 +49,7 @@ cdef class Seq(dict) :
     @definition.setter
     def definition(self, object new_definition):  # @DuplicatedSignature
         self._definition = new_definition
-        self[bytes2str(DEFINITION_COLUMN)] = new_definition
+        self[DEFINITION_COLUMN_str] = new_definition
         
         
 cdef class Nuc_Seq(Seq) :
@@ -56,7 +62,7 @@ cdef class Nuc_Seq(Seq) :
     @seq.setter
     def seq(self, object new_seq):  # @DuplicatedSignature
         self._seq = new_seq
-        self[bytes2str(NUC_SEQUENCE_COLUMN)] = new_seq
+        self[NUC_SEQUENCE_COLUMN_str] = new_seq
         
     # sequence quality property getter and setter
     @property
@@ -66,57 +72,55 @@ cdef class Nuc_Seq(Seq) :
     @quality.setter
     def quality(self, object new_quality):  # @DuplicatedSignature
         self._quality = new_quality
-        self[bytes2str(QUALITY_COLUMN)] = new_quality
+        self[QUALITY_COLUMN_str] = new_quality
         
 #    cpdef str reverse_complement(self) :    TODO in C ?
 #        pass
 
 
 cdef class Nuc_Seq_Stored(Line) :
-
-    # TODO store the str version of column name macros?
     
     # sequence id property getter and setter
     @property
     def id(self):               # @ReservedAssignment @DuplicatedSignature
-        return self[bytes2str(ID_COLUMN)]
+        return self[ID_COLUMN_str]
     
     @id.setter
     def id(self, str new_id):   # @ReservedAssignment @DuplicatedSignature
-        self[bytes2str(ID_COLUMN)] = new_id
+        self[ID_COLUMN_str] = new_id
         
     # sequence definition property getter and setter
     @property
     def definition(self):
-        return self[bytes2str(DEFINITION_COLUMN)]
+        return self[DEFINITION_COLUMN_str]
     
     @definition.setter
     def definition(self, str new_def): # @DuplicatedSignature
-        self[bytes2str(DEFINITION_COLUMN)] = new_def
+        self[DEFINITION_COLUMN_str] = new_def
         
     # nuc_seq property getter and setter
     @property
     def nuc_seq(self):
-        return self[bytes2str(NUC_SEQUENCE_COLUMN)]
+        return self[NUC_SEQUENCE_COLUMN_str]
     
     @nuc_seq.setter
     def nuc_seq(self, object new_seq): # @DuplicatedSignature
-        self[bytes2str(NUC_SEQUENCE_COLUMN)] = new_seq
+        self[NUC_SEQUENCE_COLUMN_str] = new_seq
         
     # quality property getter and setter
     @property
     def quality(self):
-        return self[bytes2str(QUALITY_COLUMN)]
+        return self[QUALITY_COLUMN_str]
     
     @quality.setter
     def quality(self, object new_qual): # @DuplicatedSignature
         if (type(new_qual) == list) or (new_qual is None) : # TODO check that quality column exists
-            self[bytes2str(QUALITY_COLUMN)] = new_qual
+            self[QUALITY_COLUMN_str] = new_qual
         else :  # Quality is in str form
-            (((self._view).columns)[bytes2str(QUALITY_COLUMN)]).set_str_line(self._index, new_qual)
+            self._view.get_column(QUALITY_COLUMN_str).set_str_line(self._index, new_qual)
             
     cpdef object get_str_quality(self) :    # TODO not ideal. Make quality_int and quality_str properties
-        return ((self._view).columns)[bytes2str(QUALITY_COLUMN)].get_str_line(self._index)
+        return self._view.get_column(QUALITY_COLUMN_str).get_str_line(self._index)
     
 #    cpdef str reverse_complement(self) :    TODO in C ?
 #        pass