def _get_subgraph(codons, G):
 subgraph = {}
 for i in codons:
  subgraph[i] = {}
  for j in codons:
   if (i != j):
    subgraph[i][j] = G[i][j]
 return subgraph

def _get_subgraph ( codons , G ) : subgraph = { } for i in codons : subgraph [ i ] = { } for j in codons : if ( i != j ) : subgraph [ i ] [ j ] = G [ i ] [ j ] return subgraph
get the subgraph that contains all codons in list .