RxPy - 将实时 Twitter 流变成 Rx Observable？答案

【问题标题】：RxPy - Turn Live Twitter Stream into Rx Observable?RxPy - 将实时 Twitter 流变成 Rx Observable？
【发布时间】：2016-11-09 01:40:42
【问题描述】：

我跟随great tutorial 使用 tweepy 在 Python 中利用实时 Twitter 流。这将实时打印提及 RxJava、RxPy、RxScala 或 ReactiveX 的推文。

from tweepy.streaming import StreamListener
from tweepy import OAuthHandler
from tweepy import Stream
from rx import Observable, Observer

#Variables that contains the user credentials to access Twitter API
access_token = "CONFIDENTIAL"
access_token_secret = "CONFIDENTIAL"
consumer_key = "CONFIDENTIAL"
consumer_secret = "CONFIDENTIAL"


#This is a basic listener that just prints received tweets to stdout.
class TweetObserver(StreamListener):

    def on_data(self, data):
        print(data)
        return True

    def on_error(self, status):
        print(status)



if __name__ == '__main__':

    #This handles Twitter authetification and the connection to Twitter Streaming API
    l = TweetObserver()
    auth = OAuthHandler(consumer_key, consumer_secret)
    auth.set_access_token(access_token, access_token_secret)
    stream = Stream(auth, l)

    #This line filter Twitter Streams to capture data by the keywords: 'python', 'javascript', 'ruby'
    stream.filter(track=['rxjava','rxpy','reactivex','rxscala'])

这是通过RxPy 变成ReactiveX Observable 的完美候选人。但是我究竟如何把它变成一个热源Observable？我似乎无法在任何地方找到有关如何执行Observable.create()...

【问题讨论】：

我记得我可以通过一个主题来完成此任务，并且我已经成功了。但仍然想知道我是否可以无主题地做到这一点......

标签： python reactive-programming tweepy reactivex rx-py

【解决方案1】：

我前段时间想通了。您必须定义一个函数来操作传递的Observer 参数。然后你将它传递给Observable.create()。

from tweepy.streaming import StreamListener
from tweepy import OAuthHandler
from tweepy import Stream
import json
from rx import Observable

# Variables that contains the user credentials to access Twitter API
access_token = "PUT YOURS HERE"
access_token_secret = "PUT YOURS HERE"
consumer_key = "PUT YOURS HERE"
consumer_secret = "PUT YOURS HERE"


def tweets_for(topics):
    def observe_tweets(observer):
        class TweetListener(StreamListener):
            def on_data(self, data):
                observer.on_next(data)
                return True

            def on_error(self, status):
                observer.on_error(status)

        # This handles Twitter authetification and the connection to Twitter Streaming API
        l = TweetListener()
        auth = OAuthHandler(consumer_key, consumer_secret)
        auth.set_access_token(access_token, access_token_secret)
        stream = Stream(auth, l)
        stream.filter(track=topics)

    return Observable.create(observe_tweets).share()


topics = ['Britain', 'France']

tweets_for(topics) \
    .map(lambda d: json.loads(d)) \
    .subscribe(on_next=lambda s: print(s), on_error=lambda e: print(e))

【讨论】：