def make_back_table(table, default_stop_codon):
 back_table = {}
 for key in sorted(table):
  back_table[table[key]] = key
 back_table[None] = default_stop_codon
 return back_table

def make_back_table ( table , default_stop_codon ) : back_table = { } for key in sorted ( table ) : back_table [ table [ key ] ] = key back_table [ None ] = default_stop_codon return back_table
back a back-table .