Day7 作业

使用一个变量all_students保存一个班的学生信息(4个)，每个学生需要保存：姓名、年龄、成绩、电话

all_students = [
    {'name':'stu1', 'age': 19, 'score':81, 'tel':'192222'},
    {'name':'stu2', 'age': 29, 'score':90, 'tel':'211222'},
    {'name':'stu3', 'age': 12, 'score':67, 'tel':'521114'},
    {'name':'stu4', 'age': 30, 'score':45, 'tel':'900012'},
] 

1.添加学生：输入学生信息，将输入的学生的信息保存到all_students中

例如输入：
姓名: 小明
年龄: 20
成绩: 100
电话: 111922  
那么就在all_students中添加{'name':'小明', 'age': 20, 'score': 100, 'tel':'111922'}

all_students = [
    {'name':'stu1', 'age': 19, 'score':81, 'tel':'192222'},
    {'name':'stu2', 'age': 29, 'score':90, 'tel':'211222'},
    {'name':'stu3', 'age': 12, 'score':67, 'tel':'521114'},
    {'name':'stu4', 'age': 30, 'score':45, 'tel':'900012'},
]
input_dict = {}
input_name = input("请输入姓名：")
input_dict['name'] = input_name
input_age = input("请输入年龄：")
input_dict['age'] = input_age
input_score = input("请输入分数：")
input_dict['score'] = input_score
input_tel = input("请输入电话：")
input_dict['tel'] = input_tel
all_students.append(input_dict)
print(all_students)

2.按姓名查看学生信息：

例如输入:
姓名: stu1 就打印：'name':'stu1', 'age': 19, 'score':81, 'tel':'192222'

all_students = [
    {'name':'stu1', 'age': 19, 'score':81, 'tel':'192222'},
    {'name':'stu2', 'age': 29, 'score':90, 'tel':'211222'},
    {'name':'stu3', 'age': 12, 'score':67, 'tel':'521114'},
    {'name':'stu4', 'age': 30, 'score':45, 'tel':'900012'},
]
input_name = input("请输入姓名：")
for student in all_students:
    if student['name'] == input_name:
        print(student)
        break
else:
    print('输入有误')

3.求所有学生的平均成绩和平均年龄

total_age = 0
total_score = 0
total_num = len(all_students)
for student in all_students:
    total_age += student['age']
    total_score += student['score']
print('平均成绩是%.2f,平均年龄是%.2f岁' % (total_score/total_num, total_age/total_num))

4.删除班级中年龄小于18岁的学生

for student in all_students[:]:
    if student['age'] < 18:
        all_students.remove(student)
print(all_students)

5.统计班级中不及格的学生的人数

fail_count = 0
for student in all_students:
    if student['score'] < 60:
        fail_count += 1
print("没有及格的学生人数是：", fail_count)

6.打印手机号最后一位是2的学生的姓名

for student in all_students:
    if student['tel'][-1] == '2':
        print(student['name'])