用python实现简易学生管理系统

以前用C++和Java写过学生管理系统，也想用Python试试，果然“人生苦短，我用Python”。用Python写的更加简洁，实现雏形也就不到100行代码。

下面上代码

#!/usr/bin/python3
# coding=utf-8


# 实现switch-case语句
class switch(object):
    def __init__(self, value):
        self.value = value
        self.fall = False

    def __iter__(self):
        """Return the match method once, then stop"""
        yield self.match
        raise StopIteration

    def match(self, *args):
        """Indicate whether or not to enter a case suite"""
        if self.fall or not args:
            return True
        elif self.value in args:  # changed for v1.5, see below
            self.fall = True
            return True
        else:
            return False


class student:
    def __init__(self, name, age, id, grade):
        self.next = None
        self.name = name
        self.age = age
        self.id = id
        self.grade = grade

    def show(self):
        print('name:', self.name, ' ', 'age:', self.age, ' ', 'id:', self.id, ' ', 'grade:', self.grade)


class stulist:
    def __init__(self):
        self.head = student('', 0, 0, 0)

    def display(self):
        p = self.head.next
        if p==None:
            print('no student data in database!')
        while p:
            p.show()
            p = p.next


    def insert(self):
        print('please enter:')
        name = input('name:')
        age = input('age:')
        id = input('id:')
        grade = input('grade:')
        newstu = student(name, age, id, grade)
        p = self.head
        while p.next:
            p = p.next
        p.next = newstu

    def query(self):
        name = input('please enter the name you want to query:')
        p = self.head.next
        if p==None:
            print('no such student in database')
        while p:
            if p.name == name:
                p.show()
            p = p.next

    def delete(self):
        name = input("please enter the student'name you want to delete:")
        p = self.head.next
        pre = self.head
        while p:
            if p.name == name:
                pre.next = p.next
                p.next = None
                print('the student info has been deleted!')
                break
            else:
                pre = p
                p = p.next


def main():
    stulist1 = stulist()
    user_input = input('please enter the OPcode:')
    while user_input:
        print('a--insert/b--display/c--query/h or ''--help/d--delete')
        for case in switch(user_input):
            if case('a'):
                stulist1.insert()
                user_input = input('please enter the OPcode:')
                break
            if case('b'):
                stulist1.display()
                user_input = input('please enter the OPcode:')
                break
            if case('c'):
                stulist1.query()
                user_input = input('please enter the OPcode:')
                break
            if case('d'):
                stulist1.delete()
                user_input = input('please enter your OPcode:')
                break
            if case():  # default
                print('please enter the OPcode...')
                user_input = input('please enter the OPcode:')
                break


if __name__ == "__main__":
    main()

下面是运行结果：