Python JSON

世界人口图

从https://datahub.io/网站搜索population，下载世界人口json数据。

from pygal.maps.world import COUNTRIES

def get_country_code(country_name):
    """根据指定的国家，返回pygal使用的两个字母的国别码"""
    for code, name in COUNTRIES.items():
        if name == country_name:
            return code
    # 如果没有找到指定的国家，就返回None
    return None


if __name__ == '__main__':
    print(get_country_code('Andorra'))
    print(get_country_code('United Arab Emirates'))
    print(get_country_code('Afghanistan'))

# world_population.py

import json
from country_codes import get_country_code
import pygal_maps_world.maps as maps
from pygal.style import RotateStyle, LightColorizedStyle

# 将数据加载到一个列表中
filename = 'data/population_data.json'
with open(filename) as f:
    pop_data = json.load(f)

# 创建一个包含人口数量的字典
cc_populations = {}

# 打印每个国家2016年的人口数量
for pop_dict in pop_data:
    for key in pop_dict:
        if key == 'Year_2016':
            country = pop_dict['Country']
            try:
                population = int(pop_dict[key])
            except:
                pass
            code = get_country_code(country)
            if code:
                print(code + ': ' + str(population))
                cc_populations[code] = population
            else:
                print('ERROR - ' + country)

# 根据人口数量将所有国家分成三组
cc_pops_1, cc_pops_2, cc_pops_3 = {}, {}, {}
for cc, pop in cc_populations.items():
    if pop < 10000000:
        cc_pops_1[cc] = pop
    elif pop < 1000000000:
        cc_pops_2[cc] = pop
    else:
        cc_pops_3[cc] = pop

# 看看每组分别包含多少个国家
print(len(cc_pops_1), len(cc_pops_2), len(cc_pops_3))

wm_style = RotateStyle('#336699', base_style=LightColorizedStyle)
wm = maps.World(style=wm_style)
wm.title = 'World Population in 2016, by Country'
wm.add('0-10m', cc_pops_1)
wm.add('10m-1bn', cc_pops_2)
wm.add('>1bn', cc_pops_3)

wm.render_to_file('world_population.svg')