Parse .ped formatted family info.
        
        Add all family info to the parser object
        
        Arguments:
            family_info (iterator): An iterator with family info

def ped_parser(self, family_info):
        """
        Parse .ped formatted family info.
        
        Add all family info to the parser object
        
        Arguments:
            family_info (iterator): An iterator with family info
        
        """
        
        for line in family_info:
            # Check if commented line or empty line:
            if not line.startswith('#') and not all(c in whitespace for c in line.rstrip()):
                splitted_line = line.rstrip().split('\t')
                if len(splitted_line) != 6:
                    # Try to split the line on another symbol:
                    splitted_line = line.rstrip().split()
                try:
                    self.check_line_length(splitted_line, 6)
                except WrongLineFormat as e:
                    self.logger.error(e)
                    self.logger.info("Ped line: {0}".format(e.ped_line))
                    raise e
                
                sample_dict = dict(zip(self.header, splitted_line))
                family_id = sample_dict['family_id']
                
                if sample_dict['family_id'] not in self.families:
                    self.families[family_id] = Family(family_id, {})
                
                ind_object = self.get_individual(**sample_dict)
                self.individuals[ind_object.individual_id] = ind_object
                self.families[ind_object.family].add_individual(ind_object)