Dean Chenensky
Published © Apache-2.0

Reddit Alexa Skill

A lambda skill for Amazon Alexa which allows users to get the newest or top post of a subreddit.

BeginnerProtip12 minutes499
Reddit Alexa Skill

Things used in this project

Hardware components

Amazon Echo
Amazon Alexa Amazon Echo
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Software apps and online services

AWS Lambda
Amazon Web Services AWS Lambda

Story

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Code

reddit-alexa.py

Python
This is the lambda_handler for when you build your lambda skill.
"""
This is the Alexa-Lambda Reddit access Skill
This version includes:
-Access to the top and new post of any subreddit

Based in the model provided in the Alexa_Python_Color_skill demo
"""

from __future__ import print_function

import praw


def lambda_handler(event, context):
    """ Route the incoming request based on type (LaunchRequest, IntentRequest,
    etc.) The JSON body of the request is provided in the event parameter.
    """
    print("event.session.application.applicationId=" +
          event['session']['application']['applicationId'])

    """
    Uncomment this if statement and populate with your skill's application ID to
    prevent someone else from configuring a skill that sends requests to this
    function.
    """
    # if (event['session']['application']['applicationId'] !=
    #         "amzn1.echo-sdk-ams.app.[unique-value-here]"):
    #     raise ValueError("Invalid Application ID")

    if event['session']['new']:
        on_session_started({'requestId': event['request']['requestId']},
                           event['session'])

    if event['request']['type'] == "LaunchRequest":
        return on_launch(event['request'], event['session'])
    elif event['request']['type'] == "IntentRequest":
        return on_intent(event['request'], event['session'])
    elif event['request']['type'] == "SessionEndedRequest":
        return on_session_ended(event['request'], event['session'])


def on_session_started(session_started_request, session):
    """ Called when the session starts """

    print("on_session_started requestId=" + session_started_request['requestId']
          + ", sessionId=" + session['sessionId'])


def on_launch(launch_request, session):
    """ Called when the user launches the skill without specifying what they
    want
    """

    print("on_launch requestId=" + launch_request['requestId'] +
          ", sessionId=" + session['sessionId'])
    # Dispatch to your skill's launch
    return get_welcome_response()


def on_intent(intent_request, session):
    """ Called when the user specifies an intent for this skill """

    print("on_intent requestId=" + intent_request['requestId'] +
          ", sessionId=" + session['sessionId'])

    intent = intent_request['intent']
    intent_name = intent_request['intent']['name']

    # Dispatch to your skill's intent handlers
    if intent_name == "MySubredditIsIntent":
        return set_subreddit_in_session(intent, session)
    elif intent_name == "WhatsTopPostIntent":
        return get_top_post_from_session(intent, session)
    elif intent_name == "WhatsNewPostIntent":
        return get_new_post_from_session(intent, session)
    elif intent_name == "AMAZON.HelpIntent":
        return get_welcome_response()
    elif intent_name == "AMAZON.CancelIntent" or intent_name == "AMAZON.StopIntent":
        return handle_session_end_request()
    else:
        raise ValueError("Invalid intent")


def on_session_ended(session_ended_request, session):
    """ Called when the user ends the session.

    Is not called when the skill returns should_end_session=true
    """
    print("on_session_ended requestId=" + session_ended_request['requestId'] +
          ", sessionId=" + session['sessionId'])
    # add cleanup logic here

# --------------- Functions that control the skill's behavior ------------------


def get_welcome_response():
    """ If we wanted to initialize the session to have some attributes we could
    add those here
    """

    session_attributes = {}
    card_title = "Welcome"
    speech_output = "Welcome to the Alexa Reddit Reader. " \
                    "Please tell me your desired subreddit by saying, " \
                    "set subreddit funny"
    # If the user either does not reply to the welcome message or says something
    # that is not understood, they will be prompted again with this text.
    reprompt_text = "Please tell me your desired subreddit by saying, " \
                    "set subreddit funny"
    should_end_session = False
    return build_response(session_attributes, build_speechlet_response(
        card_title, speech_output, reprompt_text, should_end_session))


def handle_session_end_request():
    card_title = "Session Ended"
    speech_output = "Thank you for wasting some time with me. " \
                    "Have a productive day! "
    # Setting this to true ends the session and exits the skill.
    should_end_session = True
    return build_response({}, build_speechlet_response(
        card_title, speech_output, None, should_end_session))

def set_subreddit_in_session(intent, session):
    """ Sets the subreddit in the session and prepares the speech to reply to the
    user.
    """

    card_title = intent['name']
    session_attributes = {}
    should_end_session = False

    subreddit = intent['slots']['subreddit']['value']
    session_attributes = create_subreddit_attributes(subreddit)
    speech_output = "I now know your favorite subreddit is r/" + \
                    subreddit
    reprompt_text = "You can ask me for either top or new by asking " \
                    "whats on top or whats on new"

    return build_response(session_attributes, build_speechlet_response(
        card_title, speech_output, reprompt_text, should_end_session))


def create_subreddit_attributes(subreddit):
    return {"subreddit": subreddit}

def get_top_post_from_session(intent, session):
    """ Returns the top post of a subreddit. It defaults to r/all"""
    session_attributes = {}
    reprompt_text = None

    sub_selected = "all"
    if session.get('attributes', {}) and "subreddit" in session.get('attributes', {}):
        sub_selected = session['attributes']['subreddit']

    r = praw.Reddit(user_agent='alexa_bot')
    top_post = [str(x) for x in r.get_subreddit(sub_selected).get_hot(limit=1)][0].split("::")


    speech_output = "The top post of " + sub_selected + " is " + top_post[1] + \
                    ". It has a score of " + top_post[0]

    should_end_session = False

    # Setting reprompt_text to None signifies that we do not want to reprompt
    # the user. If the user does not respond or says something that is not
    # understood, the session will end.
    return build_response(session_attributes, build_speechlet_response(
        intent['name'], speech_output, reprompt_text, should_end_session))


def get_new_post_from_session(intent, session):
    """ Returns the newest post of a subreddit. It defaults to r/all"""
    session_attributes = {}
    reprompt_text = None

    sub_selected = "all"
    if session.get('attributes', {}) and "subreddit" in session.get('attributes', {}):
        sub_selected = session['attributes']['subreddit']

    r = praw.Reddit(user_agent='alexa')
    top_post = [str(x) for x in r.get_subreddit(sub_selected).get_new(limit=1)][0].split("::")


    speech_output = "The most recent post of " + sub_selected + " is " + top_post[1] + \
                    ". It has a score of " + top_post[0]

    should_end_session = False

    # Setting reprompt_text to None signifies that we do not want to reprompt
    # the user. If the user does not respond or says something that is not
    # understood, the session will end.
    return build_response(session_attributes, build_speechlet_response(
        intent['name'], speech_output, reprompt_text, should_end_session))

# --------------- Helpers that build all of the responses ----------------------


def build_speechlet_response(title, output, reprompt_text, should_end_session):
    return {
        'outputSpeech': {
            'type': 'PlainText',
            'text': output
        },
        'card': {
            'type': 'Simple',
            'title': 'SessionSpeechlet - ' + title,
            'content': 'SessionSpeechlet - ' + output
        },
        'reprompt': {
            'outputSpeech': {
                'type': 'PlainText',
                'text': reprompt_text
            }
        },
        'shouldEndSession': should_end_session
    }


def build_response(session_attributes, speechlet_response):
    return {
        'version': '1.0',
        'sessionAttributes': session_attributes,
        'response': speechlet_response
    }

Credits

Dean Chenensky

Dean Chenensky

1 project • 0 followers

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