def fa2s2b(fastas):
s2b = {}<EOL>for fa in fastas:<EOL><INDENT>for seq in parse_fasta(fa):<EOL><INDENT>s = seq[<NUM_LIT:0>].split('<STR_LIT:>>', <NUM_LIT:1>)[<NUM_LIT:1>].split()[<NUM_LIT:0>]<EOL>s2b[s] = fa.rsplit('<STR_LIT:/>', <NUM_LIT:1>)[-<NUM_LIT:1>].rsplit('<STR_LIT:.>', <NUM_LIT:1>)[<NUM_LIT:0>]<EOL><DEDENT><DEDENT>return s2b<EOL>
convert fastas to s2b dictionary