Using stream twitter API v1.1, but HTTP error 401 raised

[sourabhch87]

I am using this code to track few terms using the Streaming API. It is reverting me an HTTP 401 error.
Please help me out to resolve this issue.

import time
import pycurl
import urllib
import json
import oauth2
API_ENDPOINT_URL = 'https://stream.twitter.com/1.1/statuses/filter.json’
USER_AGENT = 'TwitterStream 1.0’
OAUTH_KEYS = {‘consumer_key’: ‘xyz’,
‘consumer_secret’: ‘xyz’,
‘access_token_key’: ‘xyz’,
‘access_token_secret’: ‘xyz’}
POST_PARAMS = {‘include_entities’: 0,
‘stall_warning’: ‘true’,
‘track’: ‘iphone,ipad,ipod’}
class TwitterStream():
def init(self, timeout=False):
#self.oauth_token = Token(key=OAUTH_KEYS[‘access_token_key’], secret=OAUTH_KEYS[‘access_token_secret’])
self.oauth_consumer = oauth2.Consumer(key=OAUTH_KEYS[‘consumer_key’], secret=OAUTH_KEYS[‘consumer_secret’])
self.oauth_token = oauth2.Token(key=OAUTH_KEYS[‘access_token_key’], secret=OAUTH_KEYS[‘access_token_secret’])
self.conn = None #pycurl.Curl()
self.buffer = ''
self.timeout = timeout
self.setup_connection()

def setup_connection(self):
    """ Create persistant HTTP connection to Streaming API endpoint using cURL.
    """
    if self.conn:
        self.conn.close()
        self.buffer = ''
    self.conn = pycurl.Curl()
    # Restart connection if less than 1 byte/s is received during "timeout" seconds
    if isinstance(self.timeout, int):
        self.conn.setopt(pycurl.LOW_SPEED_LIMIT, 1)
        self.conn.setopt(pycurl.LOW_SPEED_TIME, self.timeout)
    self.conn.setopt(pycurl.URL, API_ENDPOINT_URL)
    self.conn.setopt(pycurl.USERAGENT, USER_AGENT)
    # Using gzip is optional but saves us bandwidth.
    self.conn.setopt(pycurl.ENCODING, 'deflate, gzip')
    self.conn.setopt(pycurl.POST, 1)
    self.conn.setopt(pycurl.POSTFIELDS, urllib.urlencode(POST_PARAMS))
    self.conn.setopt(pycurl.HTTPHEADER, ['Host: stream.twitter.com',
                                         'Authorization: %s' % self.get_oauth_header()])
    # self.handle_tweet is the method that are called when new tweets arrive
    self.conn.setopt(pycurl.WRITEFUNCTION, self.handle_tweet)

def get_oauth_header(self):
    """ Create and return OAuth header.
    """
    params = {'oauth2_version': '1.0',
              'oauth2_nonce': oauth2.generate_nonce(),
              'oauth2_timestamp': int(time.time())}
    req = oauth2.Request(method='POST', parameters=params, url='%s?%s' % (API_ENDPOINT_URL,
                                                                         urllib.urlencode(POST_PARAMS)))
    req.sign_request(oauth2.SignatureMethod_HMAC_SHA1(), self.oauth_consumer, self.oauth_token)
    return req.to_header()['Authorization'].encode('utf-8')

def start(self):
    """ Start listening to Streaming endpoint.
    Handle exceptions according to Twitter's recommendations.
    """
    backoff_network_error = 0.25
    backoff_http_error = 5
    backoff_rate_limit = 60
    while True:
        self.setup_connection()
        try:
            self.conn.perform()
        except:
            # Network error, use linear back off up to 16 seconds
            print 'Network error: %s' % self.conn.errstr()
            print 'Waiting %s seconds before trying again' % backoff_network_error
            time.sleep(backoff_network_error)
            backoff_network_error = min(backoff_network_error + 1, 16)
            continue
        # HTTP Error
        sc = self.conn.getinfo(pycurl.HTTP_CODE)
        if sc == 420:
            # Rate limit, use exponential back off starting with 1 minute and double each attempt
            print 'Rate limit, waiting %s seconds' % backoff_rate_limit
            time.sleep(backoff_rate_limit)
            backoff_rate_limit *= 2
        else:
            # HTTP error, use exponential back off up to 320 seconds
            print 'HTTP error %s, %s' % (sc, self.conn.errstr())
            print 'Waiting %s seconds' % backoff_http_error
            time.sleep(backoff_http_error)
            backoff_http_error = min(backoff_http_error * 2, 320)

def handle_tweet(self, data):
    """ This method is called when data is received through Streaming endpoint.
    """
    self.buffer += data
    if data.endswith('\r\n') and self.buffer.strip():
        # complete message received
        message = json.loads(self.buffer)
        self.buffer = ''
        msg = ''
        if message.get('limit'):
            print 'Rate limiting caused us to miss %s tweets' % (message['limit'].get('track'))
        elif message.get('disconnect'):
            raise Exception('Got disconnect: %s' % message['disconnect'].get('reason'))
        elif message.get('warning'):
            print 'Got warning: %s' % message['warning'].get('message')
        else:
            print 'Got tweet with text: %s' % message.get('text')

if name == ‘main’:
ts = TwitterStream()
ts.setup_connection()
ts.start()

Regards
Sourabh