def make_header(field_names, permit_not=False):
slug_chars = SLUG_CHARS if not permit_not else SLUG_CHARS + "<STR_LIT>"<EOL>header = [<EOL>slug(field_name, permitted_chars=slug_chars) for field_name in field_names<EOL>]<EOL>result = []<EOL>for index, field_name in enumerate(header):<EOL><INDENT>if not field_name:<EOL><INDENT>field_name = "<STR_LIT>".format(index)<EOL><DEDENT>elif field_name[<NUM_LIT:0>].isdigit():<EOL><INDENT>field_name = "<STR_LIT>".format(field_name)<EOL><DEDENT>if field_name in result:<EOL><INDENT>field_name = make_unique_name(<EOL>name=field_name, existing_names=result, start=<NUM_LIT:2><EOL>)<EOL><DEDENT>result.append(field_name)<EOL><DEDENT>return result<EOL>
Return unique and slugged field names.