Python案例：查询城市天气并绘制最高气温与最低气温的折线图

1、编写源代码 - 查询城市天气.

# -*- coding: utf-8 -*-
"""
Spyder Editor

This is a temporary script file.
"""
# 功能：查询城市天气
import requests, json, re
from matplotlib import pyplot as plt
 
# 获取城市代码
def getCityCode(city):
    url = 'http://toy1.weather.com.cn/search?cityname=' + city    
    r = requests.get(url)
    if len(r.text) > 4:
        json_arr = json.loads(r.text[1:len(r.text)-1])    
        code = json_arr[0]['ref'][0:9]
        return code
    else:
        return "000000000"
 
# 获取城市天气信息
def getWeatherInfo(city):
    code = getCityCode(city)
    url = 'http://t.weather.sojson.com/api/weather/city/' + code
    r = requests.get(url)
    info = r.json()
    weather = {}
    if info['status'] == 200:        
        weather['城市：'] = info['cityInfo']['parent'] + info['cityInfo']['city']
        weather['时间：'] = info['time'] + ' ' + info['data']['forecast'][0]['week']
        weather['温度：'] = info['data']['forecast'][0]['high'] + ' ' + info['data']['forecast'][0]['low']
        weather['天气：'] = info['data']['forecast'][0]['type']       
    else:
        weather['错误：'] = '[' + city + ']不存在！'
    return weather
 
# 打印天气信息
def printWeatherInfo(weather):
    for key in weather:
        print(key + weather[key])
    
# 获取未来气温    
def getTemperatures(city):
    code = getCityCode(city)
    url = 'http://t.weather.sojson.com/api/weather/city/' + code
    r = requests.get(url)
    info = r.json()    
    temperatures = {}
    if info['status'] == 200:    
        forecast = info['data']['forecast']
        for i in range(len(forecast)):
            dayinfo = forecast[i]            
            high = int(re.findall(r'\d+', dayinfo['high'])[0])
            low = int(re.findall(r'\d+', dayinfo['low'])[0])
            temperatures[dayinfo['ymd']] = [high, low]
    else:
        temperatures['错误：'] = '[' + city + ']不存在！'       
    return temperatures 
        
# 打印未来气温
def printTemperatures(temperatures):
    if '错误：' not in temperatures.keys():
        for key in temperatures:
            print(key + ' 高温：'+ str(temperatures[key][0]) + ' 低温：' + str(temperatures[key][1]))    
 
# 绘制未来气温折线图
def drawTemperatureLineChart():
    temperatures = getTemperatures(city)
    if '错误：' not in temperatures.keys():
        dates = []
        highs = []
        lows = []
        for key in temperatures:
            dates.append(key)
            highs.append(temperatures[key][0])
            lows.append(temperatures[key][1])
        fig = plt.figure(dpi=81, figsize=(5,4))
        plt.xlabel('Date (YYYY-MM-DD)', fontsize = 10)
        plt.ylabel("Temperature (℃)", fontsize=10)
        fig.autofmt_xdate()
        plt.plot(dates, highs, c='red', alpha=0.5)
        plt.plot(dates, lows, c='blue', alpha=0.5)    
 
city = input('输入城市名：')
printWeatherInfo(getWeatherInfo(city))
printTemperatures(getTemperatures(city))
drawTemperatureLineChart()

运行结果：