#菜单函数
def menu():
print(‘***************************学生信息管理系统*********************************‘)
print(‘-------------------------------功能菜单-------------------------------------‘)
print(‘\t\t\t\t\t\t1、录入学生信息‘)
print(‘\t\t\t\t\t\t2、查找学生信息‘)
print(‘\t\t\t\t\t\t3、删除学生信息‘)
print(‘\t\t\t\t\t\t4、修改学生信息‘)
print(‘\t\t\t\t\t\t5、排序‘)
print(‘\t\t\t\t\t\t6、统计学生总数‘)
print(‘\t\t\t\t\t\t7、显示所有学生信息‘)
print(‘\t\t\t\t\t\t0、退出‘)
print(‘***************************************************************************‘)
#主函数
def main():
while True:
menu() #调用菜单函数
choice = input(‘请输入你选择的功能：‘)
if choice in [0,1,2,3,4,5,6,7]:
if choice == ‘0‘:
answer = input(‘您确定要退出系统吗? y/n‘)
if answer == ‘y‘ or answer == ‘Y‘:
break
elif answer ==‘n‘ or answer ==‘N‘:
continue
else:
print(‘您的输入有误！请重新输入‘)
elif choice == ‘1‘:
insert()
elif choice == ‘2‘:
search()
elif choice == ‘3‘:
delete()
elif choice == ‘4‘:
modify()
elif choice == ‘5‘:
sort()
elif choice == ‘6‘:
total()
elif choice == ‘7‘:
show()
else:
print(‘您的输入有误，请重新输入！‘)
if __name__ == ‘__main__‘:
main()
def insert():
student_list[] #初始化空列表
while True:
id = input(‘请输入学生id(如1001):‘)
if not id : #如果id为空
break
try:
name = input(‘请输入姓名‘)
english = input(‘请输入英语成绩‘)
python = input(‘请输入python成绩‘)
java = input(‘请输入java成绩‘)
except:
print(‘输入无效，请输入整数‘)
continue
student = {‘id‘:id,‘name‘:name,‘english‘:english,‘python‘:python,‘java‘:java}
studnet_list.append(student)
answer = input(‘是否继续添加学生信息，y/n‘)
if answer == ‘y‘ or answer == ‘Y‘:
continue
elif answer == ‘n‘ or answer == ‘N‘:
break
else:
print(‘您的输入有误，请重新输入‘)
save(student_list)
print(‘学生信息保存成功‘)
def save(lst):
try:
stu_txt=open(filename,‘a‘,encoding=‘utf-8‘) #如果没有文件会追加改文件，filename是全局变量
except:
stu_txt=open(filename,‘w‘,encoding=‘utf-8‘)
for item in lst:
stu_txt.write(str(item)+‘\n‘)
stu_txt.close()
def delete():
while True:
student_id=input(‘请输入要删除的学生id:‘)
if studnet_id != ‘‘:
if os.path.exists(filename):
with open(filename,‘r‘,encoding=‘utf-8‘) as rfile:
student_lst=rfile.readlines()
else:
student_lst=[]
flag=False
if student_lst:
d={}
for item in student_lst:
d=dict(eval(item))
if d[id] == studnet_id:
flag=True
else:
with open(filename,‘w‘,encoding=‘utf-8‘) as wfile:
wfile.write(str(d)+‘\n)‘
if flag:
print(f‘id为{student_id}的学生信息已经被删除‘)
else:
print(f‘没有找到id为{student_id}的学生信息‘)
else：
print（‘您的输入有误，请重新输入‘）
delete()
show() #重新显示所有学生信息
answer= input(‘是否继续删除? y/n‘)
if answer == ‘y‘ or answer==‘y‘:
continue
else:
break
def modify():
show()
with open(filename,‘r‘,encoding=‘utf-8‘) as rflie:
student=rflie.readlines()
student_id=input(‘请输入要修改的学生id‘)
with open(filename,‘w‘,encoding=‘utf-8‘) as wfile:
for item in student:
d=dict(eval(item))
if d[‘id‘] == student_id:
while True：
try:
d[‘name‘]=input(‘请输入学生姓名‘)
d[‘english‘]=input(‘请输入学生英语成绩：‘)
d[‘python‘]=input(‘请输入学生python成绩：‘)
d[‘java‘]=input(‘请输入学生java成绩：‘)
except:
print(‘您的输入有误！‘)
else：
break
wfile.write(str(d)+‘\n‘)
else:
wfile.write(str(d)+‘\n‘)
answer=input(‘是否继续修改 y/n‘)
if answer==‘y‘ or answer== ‘n‘:
modify()
def search():
student_querry=[]
while True:
id=‘‘
name=‘‘
if os.path.exists(filename):
mode=input(‘按id查找请输入1，按name查找请输入2‘)
if mode == ‘1‘
id=input(‘请输入学生的的id：‘)
elif mode == ‘2‘:
name=input(‘请输入学生的的姓名：‘)
else:
print(‘您的输入有误，请重新输入‘)
search（）
with open（filename,‘r‘,encoding=‘utf-8‘）as rfile:
students=rfile.readlines
for item in studnets:
d=dict(eval(item))
if d[‘id‘] ==id :
student_querry.append(d)
elif d[‘name‘]==name:
studnet_querry.append(d)
else:
print(‘查无此人‘)
show_sutdent(studnet_querry)
studnet_querry.clear()
answer=input(‘是否继续，y/n ‘)
if answer==‘y‘ or answer==‘Y‘:
continue
else:
break
else:
return
def show_student(list):
format_title = ‘{:^6}\t{:^12}\t{:^8}\t{:^10}\t{:^8}‘
format_date = ‘{:^6}\t{:^12}\t{:^8}\t{:^10}\t{:^8}‘
if len(list) == 0:
print("查无此人")
return
print(format_title.format(‘ID‘, ‘姓名‘, ‘英语成绩‘, ‘python成绩‘, ‘java成绩‘, ‘总成绩‘))
for item in list:
print(format_date.format(item.get(‘id‘),
item.get(‘name‘),
item.get(‘english‘),
item.get(‘python‘),
item.get(‘java‘),
item.get(‘english‘) + item.get(‘python‘) + item.get(‘java‘)
))
def total():
if os.path.exists(filename):
with open(filename,‘r‘,encoding=‘utf-8‘) as rfile:
students=rfile.readlines()
if students:
print(f‘一共有{len(students)}名学生‘)
else:
print(‘无学生信息‘)
else:
print(‘无学生信息‘)
def sort():
show()
with open(filename,‘r‘,encoding=‘utf-8‘) as rfile:
student_list=rfile.readlines()
student_new=[]
for item in student_list:
d=dict(eval(item))
student_new.append(d)
asc_or_desc=input(‘升序or降序，1/2‘)
if asc_or_desc==‘1‘:
asc_or_desc_bool=False
elif asc_or_desc==‘2‘:
asc_or_desc_bool=True
else:
print(‘您的输入有误，请重新输入‘)
sort()
mode=input(‘请选择排序方式，1、按英语成绩排序；2、按python成绩排序； 3、按java成绩排序‘)
if mode==‘1‘:
student_new.sort(key=lambda x: int(x[‘english‘]) ,reverse=asc_or_desc_bool)
elif mode==‘2‘:
student_new.sort(key=lambda x: int(x[‘python‘]), reverse=asc_or_desc_bool)
elif mode==‘3‘:
student_new.sort(key=lambda x: int(x[‘python‘]), reverse=asc_or_desc_bool)
else:
print(‘您的输入有误，请重新输入‘)
sort()
show_student(student_new)
def show():
sutdnet_list[]
if os.path.exists(filename):
with open(filename,‘r‘,encoding=‘utf-8‘) as rfile:
studnets=rfile.readlines()
for item in students:
student_list.append(eval(item))
if student_list:
show_student(student_list)
else:
print(‘无学生信息‘)
原文：https://www.cnblogs.com/feixiong1/p/14122913.html