def add():
 dict1 = {}
 sName = input("请输入学生姓名：")
 sAge = eval(input("请输入学生年龄："))
 sNumber = eval(input("请输入学生学号："))
 tele_num = eval(input("请输入手机号码："))
 dict1["name"] = sName
 dict1["age"] = sAge
 dict1["sNumber"] = sNumber
 dict1["tele_num"] = tele_num
 L.append(dict1)
 print("增加成功")
 input("按任意键返回菜单")

def modify():
 num = eval(input("请输入学生学号："))
 index1 = -1
 for i,dict in enumerate(L):
 if dict.get("sNumber") == num:
 index1 = i
 break
 if index1 != -1:
 L[index1]['name'] = input("请输入新的姓名：")
 L[index1]['age'] = eval(input("请输入新的年龄："))
 L[index1]['sNumber'] = eval(input("请输入新的学号："))
 L[index1]['tele_num'] = eval(input("请输入新的手机号："))
 print("修改成功")
 else:
 print("无此学生")
 input("按任意键返回菜单")

def delete():
 num = eval(input("请输入要删除学生的学号："))
 index1 = -1
 for i, dict in enumerate(L):
 if dict.get("sNumber") == num:
 index1 = i
 break
 if index1 != -1:
 del L[index1]
 print("删除成功")
 else:
 print("无此学生")
 input("按任意键返回菜单")

def search():
 num = eval(input("请输入要查询学生的学号："))
 index1 = -1
 for i, dict in enumerate(L):
 if dict.get("sNumber") == num:
 index1 = i
 break
 if index1 != -1:
 print("姓名：%s 年龄：%d 学号：%d 手机号码：%d" % (L[index1]["name"], L[index1]["age"],  L[index1]["sNumber"], L[index1]["tele_num"]))
 else:
 print("无此学生")
 input("按任意键返回菜单")

def prin():
 if len(L) == 0:
 print("无成员")
 else:
 for dict1 in L:
 print("姓名：%s 年龄：%d 学号：%d 手机号码：%d"%(dict1["name"], dict1["age"], dict1["sNumber"], dict1["tele_num"]))
 input("按任意键返回菜单")

def write_file():
 file = open("student_list.data", 'w', encoding='utf-8')
 for i in L:
 file.write(str(i) + '\n')
 file.close()
 input("录入成功，按任意键返回菜单！")

def read_file():
 try:
 file = open("student_list.data", 'r', encoding='utf-8')
 content = file.readlines()
 for i in content:
 L.append(eval(i))
 file.close()
 input("读取完成，按任意键返回菜单！")
 except:
 print("文件不存在")