#!/usr/bin/env python3
'''
StudentList
'''

import sys


class StudentList(object):
    '''
    A student list class
    to store the information of student name and ID
    '''

    def __init__(self):
        '''
        use id as key to store the infomation
        '''
        self.studen_list = dict()

    def add_student(self, std_id, name):
        '''
        add student info
        '''
        if id not in self.studen_list.keys():
            self.studen_list[std_id] = name
        else:
            print("duplicated student id! ignored.", file=sys.stderr)

    def print_list(self):
        '''
        print the info
        '''
        for stdid, stdname in sorted(self.studen_list.items()):
            print(stdid, stdname)


class StudentList15(StudentList):
    '''
    subclass of the StudentList
    '''

    def print_list(self):
        '''
        print the info in decending order
        '''
        for stdid, stdname in sorted(self.studen_list.items(), reverse=True):
            print(stdid, stdname) 

#!/usr/bin/env python3
'''
StudentList
'''

import sys


class StudentList(object):
    '''
    A student list class
    to store the information of student name and ID
    '''

    def __init__(self):
        '''
        use id as key to store the infomation
        '''
        self.studen_list = dict()

    def add_student(self, std_id, name):
        '''
        add student info
        '''
        if id not in self.studen_list.keys():
            self.studen_list[std_id] = name
        else:
            print("duplicated student id! ignored.", file=sys.stderr)

    def print_list(self):
        '''
        print the info
        '''
        for stdid, stdname in sorted(self.studen_list.items()):
            print(stdid, stdname)


class StudentList15(StudentList):
    '''
    subclass of the StudentList
    '''

    def print_list(self):
        '''
        print the info in decending order
        '''
        for stdid, stdname in sorted(self.studen_list.items(), reverse=True):
            print(stdid, stdname) 

#!/usr/bin/env python3 StudentList A student list class     to store the information of student name and ID use id as key to store the infomation add student info print the info subclass of the StudentList print the info in decending order