# coding:utf-8

'''
    列表数据库
'''
# 使用列表list来表示数据
bob = ['陈小山',21,'男','22软件3+2']
sue = ['麦海丽',20,'女','22软件3+2']

# # 获取二人的姓名和年龄
# name = bob[0]
# age = bob[1]

# print(name,age)

# # 增加年龄
# bob[1]+=1
# print(bob)

# 构造数据库database,命名为people
people = [bob,sue]

for person in people:
    print(person)

# 新增一个人的记录(record)
tom = ['陈彬',22,'男','22软件3+2']
people.append(tom)

# 获取平均年龄
ages = [person[1] for person in people]
print(ages)

import numpy as np
avg_ages = np.mean(ages)
print(avg_ages)

# 给字段(Field)加标签
NAME,AGE,GENDER,CLASSNAME = 0,1,2,3 # range(4)

# 获取花名册
namelist = [person[NAME] for person in people]
print(namelist)

# 让值与字段名成对出现，避免数据格式变化
bob = [
    ['NAME','陈小山'],
    ['AGE',21],
    ['GENDER','男'],
    ['CLASSNAME','22软件3+2']
    ]

sue = [
    ['NAME','麦海丽'],
    ['AGE',20],
    ['GENDER','女'],
    ['CLASSNAME','22软件3+2']
    ]

people = [bob,sue]

for filed,value in bob:
    print(filed,value)

# 如何获取花名册
namelist = []
for person in people:
    for filed,value in person:
        if filed == 'NAME':
            namelist.append(value)
            break

print(namelist)

# 获取任意字段
def field(record,label):
    for filed,value in record:
        if filed == label:
            return value
        
fileds = []
for person in people:
    fileds.append(field(person,'AGE'))   # person['AGE'] =>  字典dict
print(fileds)