# 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 = []
# dict1 = {}
# # shuru = input('是否输入：')
# while True:
# shuru = input('是否输入(1.继续)：')
# if shuru == '1':
# name = input('请输入姓名：')
# age = input('请输入年龄：')
# score = input('请输入成绩：')
# tel = input('请输入电话：')
# dict1 = {'name': name, 'age': age, 'score': score, 'tel': tel}
# all_students.append(dict1)
# else:
# break
#
# print(all_students)
"""
[{'name': 'h', 'age': '20', 'score': '98', 'tel': '123'},
{'name': 'hf', 'age': '20', 'score': '88', 'tel': '234'}]
"""
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'},
# ]
# name1 = input('请输入要查找的姓名：')
# index = 0
# for dict1 in all_students[:]:
# index += 1
# if dict1['name'] == name1:
# print(index, dict1)
"""
请输入要查找的姓名：stu4
4 {'name': 'stu4', 'age': 30, 'score': 45, 'tel': '900012'}
"""
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'},
]
all_ages = 0
all_scores = 0
for item in all_students:
all_ages += item['age']
all_scores += item['score']
print('平均成绩:%.2f平均年龄:%d' % (all_scores / len(str(all_scores)), all_ages / len(str(all_ages))))
# 平均成绩:94.33平均年龄:45
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 item in all_students[:]:
if item['age']<18:
all_students.remove(item)
print(all_students)
"""
[{'name': 'stu1', 'age': 19, 'score': 81, 'tel': '192222'},
{'name': 'stu2', 'age': 29, 'score': 90, 'tel': '211222'},
{'name': 'stu4', 'age': 30, 'score': 45, 'tel': '900012'}]
"""
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'},
# ]
# count = 0
# for x in all_students:
# if x['score']<60:
# count+=1
# print(count) # 1
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:
if dict1['tel'][-1] == '2':
print(dict1['name'], end=' ') # stu1 stu2 stu4
```
