Python从网络接口爬取json天气预报数据绘制高温低温双折线图

红太狼 2023-10-18 15:28 70阅读 0赞

## Python从网络接口爬取json天气预报数据绘制高温低温双折线图 ##

实现一个功能，从网络上的天气预报接口读取天气预报中的json数据，json数据中包含高温和低温以及日期，然后把日期作为横坐标，高温和低温分别做两条折线绘制在同一张图上。  
第一步，需要从网路接口中读取json天气预报数据并解析json中包含的高温、低温数据以及对应的日期。本例中的天气预报json数据接口：http://t.weather.sojson.com/api/weather/city/101270101  
读出来的json数据格式如下所示：

{
    	"time": "2019-03-13 13:13:28",
    	"cityInfo": {
    		"city": "成都市",
    		"cityId": "101270101",
    		"parent": "四川",
    		"updateTime": "12:39"
    	},
    	"date": "20190313",
    	"message": "Success !",
    	"status": 200,
    	"data": {
    		"shidu": "64%",
    		"pm25": 83.0,
    		"pm10": 139.0,
    		"quality": "轻度污染",
    		"wendu": "14",
    		"ganmao": "儿童、老年人及心脏、呼吸系统疾病患者人群应减少长时间或高强度户外锻炼",
    		"yesterday": {
    			"date": "12",
    			"sunrise": "07:20",
    			"high": "高温 17.0℃",
    			"low": "低温 11.0℃",
    			"sunset": "19:09",
    			"aqi": 114.0,
    			"ymd": "2019-03-12",
    			"week": "星期二",
    			"fx": "无持续风向",
    			"fl": "<3级",
    			"type": "阵雨",
    			"notice": "阵雨来袭，出门记得带伞"
    		},
    		"forecast": [{
    			"date": "13",
    			"sunrise": "07:19",
    			"high": "高温 17.0℃",
    			"low": "低温 11.0℃",
    			"sunset": "19:10",
    			"aqi": 110.0,
    			"ymd": "2019-03-13",
    			"week": "星期三",
    			"fx": "无持续风向",
    			"fl": "<3级",
    			"type": "阵雨",
    			"notice": "阵雨来袭，出门记得带伞"
    		}, {
    			"date": "14",
    			"sunrise": "07:17",
    			"high": "高温 18.0℃",
    			"low": "低温 11.0℃",
    			"sunset": "19:11",
    			"aqi": 58.0,
    			"ymd": "2019-03-14",
    			"week": "星期四",
    			"fx": "无持续风向",
    			"fl": "<3级",
    			"type": "多云",
    			"notice": "阴晴之间，谨防紫外线侵扰"
    		}, {
    			"date": "15",
    			"sunrise": "07:16",
    			"high": "高温 14.0℃",
    			"low": "低温 9.0℃",
    			"sunset": "19:11",
    			"aqi": 66.0,
    			"ymd": "2019-03-15",
    			"week": "星期五",
    			"fx": "无持续风向",
    			"fl": "<3级",
    			"type": "小雨",
    			"notice": "雨虽小，注意保暖别感冒"
    		}, {
    			"date": "16",
    			"sunrise": "07:15",
    			"high": "高温 12.0℃",
    			"low": "低温 10.0℃",
    			"sunset": "19:12",
    			"aqi": 52.0,
    			"ymd": "2019-03-16",
    			"week": "星期六",
    			"fx": "无持续风向",
    			"fl": "<3级",
    			"type": "小雨",
    			"notice": "雨虽小，注意保暖别感冒"
    		}, {
    			"date": "17",
    			"sunrise": "07:14",
    			"high": "高温 14.0℃",
    			"low": "低温 10.0℃",
    			"sunset": "19:13",
    			"aqi": 65.0,
    			"ymd": "2019-03-17",
    			"week": "星期日",
    			"fx": "无持续风向",
    			"fl": "<3级",
    			"type": "小雨",
    			"notice": "雨虽小，注意保暖别感冒"
    		}, {
    			"date": "18",
    			"sunrise": "07:13",
    			"high": "高温 15.0℃",
    			"low": "低温 11.0℃",
    			"sunset": "19:13",
    			"aqi": 69.0,
    			"ymd": "2019-03-18",
    			"week": "星期一",
    			"fx": "无持续风向",
    			"fl": "<3级",
    			"type": "多云",
    			"notice": "阴晴之间，谨防紫外线侵扰"
    		}, {
    			"date": "19",
    			"sunrise": "07:11",
    			"high": "高温 14.0℃",
    			"low": "低温 9.0℃",
    			"sunset": "19:14",
    			"ymd": "2019-03-19",
    			"week": "星期二",
    			"fx": "无持续风向",
    			"fl": "<3级",
    			"type": "小雨",
    			"notice": "雨虽小，注意保暖别感冒"
    		}, {
    			"date": "20",
    			"sunrise": "07:10",
    			"high": "高温 17.0℃",
    			"low": "低温 6.0℃",
    			"sunset": "19:15",
    			"ymd": "2019-03-20",
    			"week": "星期三",
    			"fx": "东北风",
    			"fl": "<3级",
    			"type": "阴",
    			"notice": "不要被阴云遮挡住好心情"
    		}, {
    			"date": "21",
    			"sunrise": "07:09",
    			"high": "高温 17.0℃",
    			"low": "低温 7.0℃",
    			"sunset": "19:15",
    			"ymd": "2019-03-21",
    			"week": "星期四",
    			"fx": "东南风",
    			"fl": "<3级",
    			"type": "阴",
    			"notice": "不要被阴云遮挡住好心情"
    		}, {
    			"date": "22",
    			"sunrise": "07:08",
    			"high": "高温 18.0℃",
    			"low": "低温 10.0℃",
    			"sunset": "19:16",
    			"ymd": "2019-03-22",
    			"week": "星期五",
    			"fx": "东风",
    			"fl": "<3级",
    			"type": "小雨",
    			"notice": "雨虽小，注意保暖别感冒"
    		}, {
    			"date": "23",
    			"sunrise": "07:06",
    			"high": "高温 21.0℃",
    			"low": "低温 11.0℃",
    			"sunset": "19:16",
    			"ymd": "2019-03-23",
    			"week": "星期六",
    			"fx": "东南风",
    			"fl": "<3级",
    			"type": "多云",
    			"notice": "阴晴之间，谨防紫外线侵扰"
    		}, {
    			"date": "24",
    			"sunrise": "07:05",
    			"high": "高温 19.0℃",
    			"low": "低温 12.0℃",
    			"sunset": "19:17",
    			"ymd": "2019-03-24",
    			"week": "星期日",
    			"fx": "东北风",
    			"fl": "<3级",
    			"type": "小雨",
    			"notice": "雨虽小，注意保暖别感冒"
    		}, {
    			"date": "25",
    			"sunrise": "07:04",
    			"high": "高温 18.0℃",
    			"low": "低温 12.0℃",
    			"sunset": "19:18",
    			"ymd": "2019-03-25",
    			"week": "星期一",
    			"fx": "东北风",
    			"fl": "<3级",
    			"type": "小雨",
    			"notice": "雨虽小，注意保暖别感冒"
    		}, {
    			"date": "26",
    			"sunrise": "07:03",
    			"high": "高温 20.0℃",
    			"low": "低温 12.0℃",
    			"sunset": "19:18",
    			"ymd": "2019-03-26",
    			"week": "星期二",
    			"fx": "东风",
    			"fl": "<3级",
    			"type": "小雨",
    			"notice": "雨虽小，注意保暖别感冒"
    		}, {
    			"date": "27",
    			"sunrise": "07:02",
    			"high": "高温 20.0℃",
    			"low": "低温 13.0℃",
    			"sunset": "19:19",
    			"ymd": "2019-03-27",
    			"week": "星期三",
    			"fx": "东南风",
    			"fl": "<3级",
    			"type": "阴",
    			"notice": "不要被阴云遮挡住好心情"
    		}]
    	}
    }

第二步，高温，低温，日期数据具备后，开始绘制折线图。  
程序代码如下所示：

import json
    import urllib.request
    import matplotlib
    from matplotlib import pyplot as plt
    from datetime import datetime
    
    
    def get_weather_json_data():
        #101270101，天气预报中成都的代码。
        url = "http://t.weather.sojson.com/api/weather/city/101270101"
        response = urllib.request.urlopen(url)
        content = response.read().decode('utf-8')
        return content
    
    
    def get_forecast_data(content):
        data = content["data"]
        return data["forecast"]
    
    
    #清洗数据。过滤℃
    def get_pure_temperature(temp):
        a, b = temp.split()
        return b.strip().strip("℃")
    
    
    def make_chart(high, low, date_time):
        matplotlib.rc('font', family='SimHei', weight='bold')
        plt.rcParams['axes.unicode_minus'] = False
    
        x = range(len(date_time))
    
        plt.plot(x, low, ms=10,marker='*', color='blue', alpha=0.5, label="低温")
        plt.plot(x, high, ms=10,marker='o', color='red', alpha=0.5, label="高温")
    
        plt.fill_between(x, low, high, facecolor='gray', alpha=0.1)
        plt.title("2019年3月 - 温度变化", fontsize=15)
    
        plt.xticks(x, date_time, rotation=20)
        
        plt.xlabel('日期')
        plt.ylabel('温度')
        plt.grid()  # 显示网格
        plt.legend()
        plt.show()
    
    
    content = json.loads(get_weather_json_data())
    data = get_forecast_data(content)
    
    high, low, date_time = [], [], []
    for obj in data:
        h = obj["high"]
        high.append(get_pure_temperature(h))
    
        l = obj["low"]
        low.append(get_pure_temperature(l))
    
        date_time.append(obj["ymd"])
    
    
    
    #取得高温低温和日期，开始绘折线图。
    make_chart(high, low, date_time)

运行结果如图：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly96aGFuZ3BoaWwuYmxvZy5jc2RuLm5ldA_size_16_color_FFFFFF_t_70][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly96aGFuZ3BoaWwuYmxvZy5jc2RuLm5ldA_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20190313175919329.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly96aGFuZ3BoaWwuYmxvZy5jc2RuLm5ldA==,size_16,color_FFFFFF,t_70