Python3——处理JSON格式的文件数据

'''
The i18n module was removed in pygal-2.0.0.
 however, it can now be found in the pygal_maps_world plugin.
You can install that with pip install pygal_maps_world.
Then you can access COUNTRIES as pygal.maps.world.COUNTRIES:
from pygal.maps.world import COUNTRIES
Whats left of the i18n module can be imported with:
from pygal_maps_world import i18n
'''
#获取两个字母的国别码
from pygal_maps_world.i18n import COUNTRIES
def get_country_code(country_name):
    for code,name in COUNTRIES.items():
        if name==country_name:
            return code
        return None

import json
from Country_codes import get_country_code
#提取相关数据
filename='population_data.json'
with open(filename) as f:
    pop_data=json.load(f) #json.load()将数据转换为Python能够处理的格式并存储在pop_data中
    for pop_dict in pop_data:
        #获得每个国家2010年的人口数量
        if pop_dict['Year']=='2010':
            country_name=pop_dict['Country Name']
            population=int(float(pop_dict['Value']))#先将字符串转换为浮点数，再将浮点数转换为整数
            code=get_country_code(country_name)  #获得国家的国别码
            if code:
                print(code+':'+str(population))
            else:
                print('ERROR-'+country_name)