def iso_abundance(self,isos):
if type(isos) == list:<EOL><INDENT>dumb = []<EOL>for it in range(len(isos)):<EOL><INDENT>dumb.append(isos[it].split('<STR_LIT:->'))<EOL><DEDENT>ssratio = []<EOL>isos = dumb<EOL>for it in range(len(isos)):<EOL><INDENT>ssratio.append(self.habu[isos[it][<NUM_LIT:0>].ljust(<NUM_LIT:2>).lower() + str(int(isos[it][<NUM_LIT:1>])).rjust(<NUM_LIT:3>)])<EOL><DEDENT><DEDENT>else:<EOL><INDENT>isos = isos.split('<STR_LIT:->')<EOL>ssratio = self.habu[isos[<NUM_LIT:0>].ljust(<NUM_LIT:2>).lower() + str(int(isos[<NUM_LIT:1>])).rjust(<NUM_LIT:3>)]<EOL><DEDENT>return ssratio<EOL>
This routine returns the abundance of a specific isotope.
Isotope given as, e.g., 'Si-28' or as list
['Si-28','Si-29','Si-30']