Python：matplotlib一表多图一图多表

「爱情、让人受尽委屈。」 2022-12-28 00:53 102阅读 0赞

在一张图中画4条折线。举例，读取北京、成都、上海、深圳四城市的天气预报气温数据，然后在一张图中用四根折线绘制气温变化。

Python代码如下：

import pandas as pd
    import matplotlib.pyplot as plt
    import requests
    import re
    import json
    
    CITY = {'北京': 101010100, '成都': 101270101, '上海': 101020100, '深圳': 101280601}
    MARKER = ['^', 'o', 's', 'X']
    
    DEBUG = False
    
    
    # 根据字典的值value获得该值对应的key
    def get_dict_key(dic, value):
        keys = list(dic.keys())
        values = list(dic.values())
        idx = values.index(value)
        key = keys[idx]
        return key
    
    
    def get_data(city_code):
        if DEBUG:
            f = open('w.json', mode='r', encoding='utf-8')
            ss = f.read()
            js = json.loads(ss)
        else:
            url = f'http://t.weather.itboy.net/api/weather/city/{city_code}'
            r = requests.get(url=url)
            js = r.json()
    
        forecast = js['data']['forecast']
        df = pd.DataFrame(data=forecast)
    
        date = df['ymd']
        temp_high = df['high']
        temp_high = [int(re.findall(r'\d+', v)[0]) for v in temp_high]
        temp_low = df['low']
        temp_low = [int(re.findall(r'\d+', v)[0]) for v in temp_low]
    
        return (date, temp_low, temp_high, city_code)
    
    
    def draw_line(axs, data, i):
        axs[i].plot(data[2 * i][0],
                    data[2 * i][1],
                    color='red',
                    linewidth=1,
                    linestyle='--',
                    marker=MARKER[2 * i],
                    markerfacecolor='blue',
                    markersize=10,
                    label=get_dict_key(CITY, data[2 * i][3]))
    
        axs[i].plot(data[2 * i + 1][0],
                    data[2 * i + 1][1],
                    color='blue',
                    linewidth=2,
                    linestyle='-',
                    marker=MARKER[2 * i + 1],
                    markerfacecolor='red',
                    markersize=10,
                    label=get_dict_key(CITY, data[2 * i + 1][3]))
    
        axs[i].set_xlabel('日期')
        axs[i].set_ylabel(
            '低温(' + get_dict_key(CITY, data[2 * i][3]) + '/' + get_dict_key(CITY, data[2 * i + 1][3]) + ')')
        axs[i].grid(True)
    
    
    def main():
        data = []
        for code in list(CITY.values()):
            data.append(get_data(code))
    
        plt.rcParams['font.sans-serif'] = ['SimHei']  # 中文乱码
        plt.rcParams['axes.unicode_minus'] = False  # 正负号
    
        fig, axs = plt.subplots(nrows=2, ncols=1, constrained_layout=False)
    
        for i in range(len(axs)):
            draw_line(axs, data, i)
    
        for i in range(len(axs)):
            for tick in axs[i].get_xticklabels():
                tick.set_rotation(60)
    
        plt.title("北京-成都-上海-深圳低温变化", fontdict=dict(color='r'))
        fig.tight_layout()
    
        plt.legend()
        plt.show()
    
    
    if __name__ == '__main__':
        main()

输出结果：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW5ncGhpbA_size_16_color_FFFFFF_t_70][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW5ncGhpbA_size_16_color_FFFFFF_t_70]: /images/20221120/3a7a2cb708b447d9b07cfd0c2bca80bd.png