Python数据可视化：CSV、JSON

"""country_codes.py"""

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

"""JSON"""

import json, pygal
import pygal.style
from country_codes import get_country_code

filename = 'population_data.json'
with open(filename) as f:
    pop_data = json.load(f)

cc_populations = {}
for pop_dict in pop_data:
    if pop_dict['Year'] == '2010':
        country_name = pop_dict['Country Name']
        population = int(float(pop_dict['Value']))
        code = get_country_code(country_name)
        if code:
            cc_populations[code] = population

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

wm_style = pygal.style.RotateStyle('#336699', base_style=pygal.style.LightColorizedStyle)
wm = pygal.maps.world.World(style=wm_style)
wm.title = 'World Population in 2010, 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')

"""CSV"""

import csv

from matplotlib import pyplot as plt
from datetime import datetime

filename = 'death_valley_2014.csv'
with open(filename) as f:
    reader = csv.reader(f)
    header_row = next(reader)

    dates, highs, lows,= [], [], []
    for row in reader:
        try:
            current_date = datetime.strptime(row[0], "%Y-%m-%d")
            high = int(row[1])
            low = int(row[3])
        except:
            print(current_date, 'missing data')
        else:            
            dates.append(current_date)   
            highs.append(high)
            lows.append(low)

fig = plt.figure(dpi=128, figsize=(10, 6))
plt.plot(dates, highs, c='red', alpha=0.5)
plt.plot(dates, lows, c='blue', alpha=0.5)
plt.fill_between(dates, highs, lows, facecolor='blue', alpha=0.1)

title = "Daily high and low temperatures - 2014\nDeath Valley, CA"
plt.title(title, fontsize=20)
plt.xlabel('', fontsize=16)
fig.autofmt_xdate()
plt.ylabel("Temperature (F)", fontsize=16)
plt.tick_params(axis='both', which='major', labelsize=16)

plt.show()