Day8 课后作业

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'}

new_student = {}
print('请输入学生信息')
new_name = input('请输入姓名：')
new_student['name'] = new_name
new_age = int(input('请收入年龄：'))
new_student['age'] = new_age
new_score = float(input('请输入分数：'))
new_student['score'] = new_score
new_tel = int(input('请输入电话：'))
new_student['tel'] = new_tel
all_students.append(new_student)

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'

name = input('请输入要查看的学生姓名：')
for student in all_students:
    for key in student:
        if student[key] == name:
            print(student)

3.求所有学生的平均成绩和平均年龄

sum_score = 0
sum_age = 0
for student in all_students:
    score,age = student['score'],student['age']
    sum_score += int(score)
    sum_age += int(age)
print('所有学生的平均分是%.1f，平均年龄是%.1f' % (sum_score / len(all_students),sum_age / len(all_students)))

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)

5.统计班级中不及格的学生的人数

reject = 0
for student in all_students:
    if student['score'] < 60:
        reject += 1
print('不及格的人数为：',reject)

6.打印手机号最后一位是2的学生的姓名

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