python怎么调用百度api，python使用百度api获取天气的例子

#!/usr/bin/env python
#
__author__ = 'saint'
import os
import urllib.request
import urllib.parse
import json
class weather(object):
    # 获取城市代码的uri
    code_uri = "http://apistore.baidu.com/microservice/cityinfo?cityname="
    # 获取天气信息的uri
    weather_uri = "http://apistore.baidu.com/microservice/weather?cityid="
    # 主处理逻辑
    def mainHandle(self):
        print("输入你要查询的天气：")
        city_name = input()
        uri = self.code_uri + urllib.parse.quote(city_name)
        ret = json.loads(urllib.request.urlopen(uri).read().decode("utf8"))
        if ret['errNum'] != 0:
            print(ret['retMsg'])
            return False
        else:
            weather_uri = self.weather_uri + ret['retData']['cityCode']
            data = json.loads(urllib.request.urlopen(weather_uri).read().decode("utf8"))
            if data['errNum'] == 0:
                ret_data = data['retData']
                output = "城市名:" + city_name + "rn"
                output += "更新时间:" + ret_data["date"] + " " + ret_data["time"] + "rn"
                output += "天气:" + ret_data["weather"] + " [" + ret_data["WD"] + ret_data["WS"] + "]rn"
                output += "当前温度:" + ret_data["temp"] + " (" + ret_data["h_tmp"] + " ---> " + ret_data["l_tmp"] + ")rn"
                print(output)
                return True
            else:
                print(data['errMsg'])
                return False
if __name__ == "__main__":
    weather = weather()
    weather.mainHandle()