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：