OpenWeatherMap weather forcast tweet from AWS Lambda

WeatherForcastFromLambda.py

#coding:utf-8
from requests_oauthlib import OAuth1Session
from datetime import datetime
import json, urllib2

CK = '*****'
CS = '*****'
AT = '*****'
AS = '*****'

twUrl = 'https://api.twitter.com/1.1/statuses/update.json'

owmUrl = 'http://api.openweathermap.org/data/2.5/weather?id=1862415&APPID=*****'

def handler(event, context):
    try:
        ret = urllib2.urlopen(owmUrl)
        root = json.loads(ret.read())
    
        temp = root['main']['temp'] 
        temp = str(temp - 273.15)
        weather = root['weather']
        city = root['name']
        country = root['sys']['country']

        for details in weather:
            status = details['main']
            desc = details['description']

        dt = datetime.now().strftime("%Y/%m/%d %H:%M")
        
        msg = ''
        msg = msg + 'Weather Forecast' + ' (' + dt + ')' +'\r\n'
        msg = msg + city + ',' + country + '\r\n'
        msg = msg + 'Weather : ' + status + ' (' + desc + ')' + '\r\n'
        msg = msg + 'Temp : ' + temp + u'℃' + '\r\n'

        params = {"status": msg }

        twitter = OAuth1Session(CK, CS, AT, AS)
        req = twitter.post(twUrl, params = params)

        if req.status_code == 200:
            return msg
        else:
            return req.status_code
    finally:
        ret.close()