def add_header(self, entry):
info = entry.split('<STR_LIT:\t>')<EOL>self.n_individuals = len(info)-<NUM_LIT:9><EOL>for i,v in enumerate(info[<NUM_LIT:9>:]):<EOL><INDENT>self.individuals[v] = i<EOL><DEDENT>return self.n_individuals > <NUM_LIT:0><EOL>
Parses the VCF Header field and returns the number of samples in the VCF file