非常简单的教程，讲怎么给 Alexa 添加新的 skill，让你的 Echo 更个性化。本篇添加的 skill 是让 Alexa 从 reddit 上读前 10 条热点。

代码戳Alexa-Starter-RedditReader，其他版本如用 Lambda Function 实现，见Alexa 开发新技能 - Lambda

Requirements

Code for new skill

这里我们用 Flask 来建一个简单的 web application，代码如下，get_headlines() 是我们主要的 method，从 Reddit 里返回 10 条热点。逻辑是这样的：

(用户呼唤 Reddit Reader)
Alexa 问用户 ‘Hello there, would you like the news?’
用户回答
肯定回复: 读 10 headlines
否定回复: 回答 ‘I am not sure why you asked me to run then, but okay… bye’

注意要确保有上面的 python package，如果没有，先安装

flask == 0.12.1
flask_ask == 0.9.3
unidecode == 0.4.20

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$ pip install flask
$ pip install flask_ask
$ pip install unidecode

代码

from flask import Flask, render_template
from flask_ask import Ask, statement, question, session
import json
import requests
import time
import unidecode
# define Flask app
app = Flask(__name__)
# give basic endpoint, can be flask skill/program endpoint
ask = Ask(app, "/reddit_reader")
def get_headlines():
    sess = requests.Session()
    # just change user-agent
    sess.headers.update({'User-Agent': 'I am testing Alexa'})
    time.sleep(1)
    # get first 10 headlines
    url = 'https://reddit.com/r/worldnews/.json?limit=10'
    html = sess.get(url)
    data = json.loads(html.content.decode('utf-8'))
    titles = [unidecode.unidecode(listing['data']['title']) for listing in data['data']['children']]
    titles = '...'.join([i for i in titles])
    return titles
# set home url path
@app.route('/')
def homepage():
    return 'hi there, how ya doin?'
@ask.launch
def start_skill():
    # it will say
    welcome_message = 'Hello there, would you like the news?'
    # question expect response
    return question(welcome_message)
# handle user input yes or no response
# user input is intent
@ask.intent("YesIntent")
def share_headlines():
    # grab the headline
    headlines = get_headlines()
    headline_msg = 'The current world news headlines are {}'.format(headlines)
    # statement tell you sth
    return statement(headline_msg)
@ask.intent("NoIntent")
def no_intent():
    bye_text = 'I am not sure why you asked me to run then, but okay... bye'
    return statement(bye_text)
if __name__ == '__main__':
    app.run(debug=True)

Set endpoint

这里我们用 ngrok，将本地 web 服务部署到公共网络。如果没有下载，先从这下载并解压，然后运行，端口就是 Flask 运行的端口

1	$ ./ngrok http 5000

Deploy

去Amazon developer 网站上注册用户并登陆，注意这里的用户名和你的 Echo 用户名是一致的。点开 Alexa tab，选择 add skill，开始部署。

Step1:
填写 Name 和 Invocation Name，Invocation Name 用来 invoke app

Step2:
主要填写 Intent Schema 和 Sample Utterances

Intent Schema: how alexa will traverse your application

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{ "intents": [{ "intent": "YesIntent" },
			  { "intent": "NoIntent" }]
}

Sample Utterances: the words people say to trigger intent

YesIntent yes
YesIntent sure
NoIntent no
NoIntent go away

Step3:
选择并填写 Endpoint，这里我们用的是 HTTPS，可以在 ngrok 的命令行找到 endpoint url

Step4:
这里我们就选 My development endpoint is a sub-domain of a domain that has a wildcard certificate from a certificate authority，作为测试的话不选也没有关系

Step5:
就可以用 Echo 来 test 啦~ 如果没有 Echo，可以用 Service Simulator 来模拟
先给 Alexa 一个关于 Reddit Reader 的指令，然后按照我们的代码，Alexa 会问你要不要读新闻

然后我们回答 yes，Alexa 就开始读新闻啦~

一个简单的实例PNC_Virtual_Assistant

参考链接
Intro and Skill Logic - Alexa Skills w/ Python and Flask-Ask Part 1
Flask Building Responses