day8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'},
] 

all_studens = []
for x in range(1,5):
    new_name = input('请输入第%位学生姓名：' % x)
    new_age = int(input('请输入第%位学生年龄：'% x))
    new_score = int(input('请输入第%位学生成绩：'% x))
    new_tel = int(input('请输入第%位学生电话：'% x))
    dict1 = {'name':new_name,'age':new_age,'score':new_score,'tel':new_tel}
    all_studens.append(dict1)
print(all_studens)

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

while True:
    char = input('是否输入信息：')
    if char == '是'：
        name = input('输入姓名：')
        age = int(input('输入年龄：'))
        score = int(input('输入成绩：'))
        tel = int(input('输入电话：')）
        dict1 = {'name':name,'age':age,'score':score,'tel':tel}
print(dict1)

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'}

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'

list1 = [
    {'name':'stu1','age':18,'score':89,},
    {'name':'stu2','age':28,'score':65,},
    {'name':'stu3','age':23,'score':75,},
    {'name':'stu4','age':25,'score':99,}
]
new_name = input('输入学生姓名：')
count = 0
for dict1 in list1:
    if new_name == dict1['name']
        print(dict1)
        count += 1
if count == 0:
    print('没有该学生')

3.求所有学生的平均成绩和平均年龄

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'},
] 
new_age = 0
new_score = 0
for dict1 in all_studens:
    age = dict1['age']
    score = dict1['score']
    new_age += age
    new_score += score
avre_age = new_age / len(all_studens)
avre _score = new_score / len(all_studens)
print('所有学生的平均成绩为：%.1f,平均年龄：%.1f' % (avre_score,avre_age))

4.删除班级中年龄小于18岁的学生

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'},
] 
for dict1 in all_students:
    if dict1['age']  < 18:
        dict1.clear()
print(all_students)

5.统计班级中不及格的学生的人数

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'},
] 

num = 0
for dict1 in all_students:
    if dict1['score'] <60:
        num +=  1
print('班级中不及格的学生的人数：%d' % num)

6.打印手机号最后一位是2的学生的姓名

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'},
] 
for dict1 in all_students:
    char = dict1['tel']
    if char[-1] == '2':
        print(dict1['name'])