python实现简易版学生成绩管理系统

时间:2021-05-22

300来行python代码实现简易版学生成绩管理系统,供大家参考,具体内容如下

使用链表来实现

class Node(object): def __init__(self, data, pointer): self.data = data self.next = pointer# 创建单链表class SingleLinkedList(object): def __init__(self): self.head = Node(None, None) self.point = self.head def append(self, data): # 末尾追加节点 new_node = Node(data, None) self.point.next = new_node self.point = new_node def insert(self, data, find): # 插入数据(前向插入数据) if not self.head.next: print('链表为空') return None new_node = Node(data, None) self.point = self.head while self.point.next.data != find: self.point = self.point.next if self.point.next is None: print('没有找到该元素') return None new_node.next = self.point.next self.point.next = new_node def delete(self, find): # 删除节点 # 空链表 if not self.head.next: print('链表为空') return None self.point = self.head while self.point.next.data != find: self.point = self.point.next pointer = self.point.next self.point.next = self.point.next.next del pointer def insert_after_head(self, data): node = Node(data, None) # bug 产生没写 if 返回 if not self.head.next: self.head.next = node return None node.next = self.head.next self.head.next = node def reverse(self): local_list = SingleLinkedList() self.point = self.head count = 0 while self.point.next: count += 1 self.point = self.point.next data = self.point.data local_list.insert_after_head(data) return local_list def get_size(self): count = 0 self.point = self.head while self.point.next: self.point = self.point.next count += 1 return count def delete_by_tail(self, num): size = self.get_size() assert (num <= size) assert (num > 0) pos = size - num count = 0 self.point = self.head while count < size: count += 1 self.point = self.point.next if count == pos: pointer = self.point.next self.point.next = self.point.next.next del pointer # 求中间节点 只允许遍历一次 def quick_middle(self): slow_point = self.head fast_point = self.head while fast_point.next.next: slow_point = slow_point.next fast_point = fast_point.next.next if not fast_point.next: break if fast_point.next: slow_point = slow_point.next return slow_point.data def check_circle(self): pass def sort(self): # get_size()改变了 self.point 的指向 length = self.get_size() i, j = 0, 0 flag = 1 while i < length: self.point = self.head.next while j < length - i - 1: if self.point.data > self.point.next.data: temp = self.point.data self.point.data = self.point.next.data self.point.next.data = temp self.point = self.point.next j += 1 flag = 0 if flag: break i += 1 j = 0 def print(self): # 打印结点 self.point = self.head while self.point.next: self.point = self.point.next print('{} ->'.format(self.point.data), end=' ') print('')class StudentControlSystem(SingleLinkedList): # 打印菜单 def print_menu(self): print('*' * 30) print('-' * 13 + '菜单' + '-' * 13) print('1.增加学生信息') print('2.删除学生信息') print('3.修改学生信息') print('4.查找学生信息') print('5.显示所有信息') print('6.排序') print('0.退出程序') print('*' * 30) # 用户输入 def user_input(self, item): try: item = int(item) except: pass # 增加信息 if item == 1: self.add_info() # 删除信息 elif item == 2: find = input('请输入删除的学号:') self.del_info(find=find) # 修改信息 elif item == 3: self.modify_info() # 查找信息 elif item == 4: self.search_info() # 显示信息 elif item == 5: self.display_info() # 信息排序 elif item == 6: self.rank_info() # 退出程序 保存数据 elif item == 0: with open('database.txt', 'w') as f: self.point = self.head while self.point.next: self.point = self.point.next f.writelines('{}\n'.format(self.point.data)) exit() else: print('请输入正确的数字') # id 保证互异性 def unique_id(self, std_id): self.point = self.head while self.point.next: self.point = self.point.next if self.point.data['id'] == std_id: return False return True # 增加信息 def add_info(self): # id 不能重复 # 成绩不能超出范围 name = input('姓名:') std_id = input('学生id:') while not self.unique_id(std_id=std_id): print('id重复') std_id = input('学生id:') grade = input('学生成绩:') if eval(grade) < 0 or eval(grade) > 100: print('超出范围') grade = input('学生成绩:') print(name, std_id, grade) print('请确认无误后保存') choice = input('y/n') items = ['y', 'yes', 'Y', 'Yes'] if choice in items: print(choice) data = {'id': std_id, 'name': name, 'grade': grade} self.append(data) # 删除信息 def del_info(self, find): print('请确认无误后保存') choice = input('y/n') items = ['y', 'yes', 'Y', 'Yes'] if choice in items: if not self.head.next: print('链表为空') return None self.point = self.head while self.point.next.data['id'] != find: self.point = self.point.next pointer = self.point.next self.point.next = self.point.next.next del pointer # 序列逆序 def reverse(self): local_list = StudentControlSystem() self.point = self.head count = 0 while self.point.next: count += 1 self.point = self.point.next data = self.point.data local_list.insert_after_head(data) return local_list # 序列排序 def sort(self, item): length = self.get_size() i, j = 0, 0 flag = 1 while i < length: self.point = self.head.next while j < length - i - 1: if int(self.point.data[item]) > int(self.point.next.data[item]): # self.point.data, self.point.next.data = # self.point.next.data, self.point.data temp = self.point.data self.point.data = self.point.next.data self.point.next.data = temp self.point = self.point.next j += 1 flag = 0 if flag: break i += 1 j = 0 # 修改信息 def modify_info(self): find = input('输入需要修改的学生的id:') if not self.head.next: print('链表为空') return None self.point = self.head while str(self.point.next.data['id']) != find: self.point = self.point.next if self.point.next is None: print('没有找到该元素') return None name = input('姓名:') grade = input('学生成绩:') self.point.next.data['name'] = name self.point.next.data['grade'] = grade # 搜索信息 def search_info(self): find = input('输入需要查找的学生的id:') if not self.head.next: print('链表为空') return None self.point = self.head while str(self.point.next.data['id']) != find: self.point = self.point.next if self.point.next is None: print('没有找到该元素') return None data = self.point.next.data print('ID 姓名 成绩') print('{} {} {}'.format(data['id'], data['name'], data['grade'])) # 信息排序 def rank_info(self): choice = input('1.成绩排序 2.学号排序:') order = input('1.升序 2.降序:') if choice == '1': item = 'grade' elif choice == '2': item = 'id' else: return None self.sort(item=item) if order == '2': temp = self.reverse() temp.display_info() return None self.display_info() # 显示信息 def display_info(self): self.point = self.head print('ID 姓名 成绩') while self.point.next: self.point = self.point.next data = self.point.data print('{} {} {}'.format(data['id'], data['name'], data['grade'])) print('')def main(): SCS = StudentControlSystem() try: with open('database.txt', 'r') as f: for data in f.readlines(): SCS.append(eval(data)) except: with open('database.txt', 'w') as f: pass while True: SCS.print_menu() item = input('请输入你的选择:') SCS.user_input(item)if __name__ == "__main__": main()

运行后

然后就可以插入与查询啦

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