2018-09-03day11-作业

1.提取data.json中的数据，将每条数据中的name、text、love和comment信息。并且保存到另外一个json文件中

import json
with open('./files/data.json', 'r', encoding='utf-8') as f:
    contents = json.load(f)
    data = contents['data']
f.close()
list1 = []
for msg in data:
    new_data = {'name': msg['name'], 'text': msg['text'], 'love': msg['love'], 'comment': msg['comment']}
    list1.append(new_data)
with open('./files/new_data.json', 'w', encoding='utf-8') as f:
    json.dump(list1, f, ensure_ascii=False, indent=4)
f.close()

2.统计data.json中comment数量超过1000的个数

import json
with open('./files/data.json', 'r', encoding='utf-8') as f:
    contents = json.load(f)
    data = contents['data']
f.close()
count = 0
for msg in data:
    if int(msg['comment']) > 1000:
        count += 1
print(count)

3.将data.json文件中所有点赞数(love)对应的值超出1000的用k来表示，例如1000修改为1k, 1345修改为1.3k

import json
with open('./files/data.json', 'r', encoding='utf-8') as f:
    contents = json.load(f)
    data = contents['data']
f.close()
for msg in data:
    if int(msg['love']) >= 1000:
         msg['love'] = str(round(int(msg['love'])/1000, 1)) + 'k'
with open('./files/data.json', 'w', encoding='utf-8') as f:
    json.dump(contents, f, ensure_ascii=False, indent=4)
f.close()

4.写猜数字游戏，如果输入有误，提示重新输入，直达输入正确为止。比如：输入数字的时候没有按要求输入，提示重新输入

import random
num = random.randint(0,100)
try:
    num1 = int(input('请输入数字(0-100):'))
    while True:
        if num1 == num:
            print('恭喜你，猜对了！！！')
            break
        else:
            if num1 > num:
                print('大了，再小点！')
                num1 = int(input('请重新猜:'))
            else:
                print('小了，再大点！')
                num1 = int(input('请重新猜:'))
except ValueError:
    num1 = int(input('您的输入有误，请重新输入:'))

运行结果：
请输入数字(0-100):aa
您的输入有误，请重新输入:

5.写学生管理系统的添加学生功能(数据需要本地化)，要求除了保存学生的基本信息以外还要保存学生的学号，但是学号需要自动生成
生成原则：

添加第一个学生对应的学号是:py001 第二次添加的学生的学号是:py002 ... 如果前面的学生因为各种原因被移除了，那后面添加学生的时候原则不变，就是比如上次已经添加到py012,那么前面不管有没有删除情况，再次添加学生的学号是py013

import json
key_students = 'students'
key_number = 'number'
key_name = 'name'
key_age = 'age'
key_tel = 'tel'
key_id = 'id'
def read_data(filename):
    try:
        with open('./files/'+filename, 'r', encoding='utf-8') as f:
            return json.load(f)
    except:
        return None

def write_data(filename,contents):
    try:
        with open('./files/'+filename, 'w', encoding='utf-8') as f:
            json.dump(contents, f, ensure_ascii=False, indent=4)
            return True
    except:
        return False

def get_system_info():
    system_info = read_data('stu.json')
    if system_info:
        return system_info
    else:
        return {}

def create_id():
    system_info = get_system_info()
    number = system_info.get(key_number,0)
    number += 1
    id = 'python' + str(number).rjust(3,'0')
    return id,number

while True:
    print('===================')
    print('1.添加学生\n2.退出')
    print('===================')
    value = input('请选择:')
    if value == '1':
        name = input('请输入学生名字:')
        age = input('请输入学生年龄:')
        tel = input('请输入学生电话:')
        id,number = create_id()
        stu = {key_name:name, key_age:age, key_id:id, key_tel:tel}
        # 保存学生信息
        system_info = get_system_info()
        students = system_info.get(key_students,[])
        students.append(stu)

        # 保存到文件中
        system_info[key_students] = students
        system_info[key_number] = number
        re = write_data('stu.json',system_info)
        if re:
            print('添加成功！')
        else:
            print('添加失败！')
    elif value == '2':
        break
    else:
        continue