python-twitter / twitter.py

#!/usr/bin/python2.4

#

# Copyright 2007 Google Inc. All Rights Reserved.

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

#     http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

'''A library that provides a python interface to the Twitter API'''

__author__ = 'dewitt@google.com'

__version__ = '0.6-devel'

import base64

import calendar

import os

import rfc822

import simplejson

import sys

import tempfile

import textwrap

import time

import urllib

import urllib2

import urlparse

import twitter_pb2

try:

  from hashlib import md5

except ImportError:

  from md5 import md5

CHARACTER_LIMIT = 140

class TwitterError(Exception):

  '''Base class for Twitter errors'''

  @property

  def message(self):

    '''Returns the first argument used to construct this error.'''

    return self.args[0]

def _CopyProperty(source, destination, name, destination_name=None):

  '''Optionally copies a property from source to destination.

  Properties will be copied if and only if they appear in the dict

  and are not None.

  Args:

    source: A python dict

    destination: A python object with a property accessor

    name: The name of the source property

    destination_name: The name of the destination property, if different from name

  '''

  if destination_name is None:

    destination_name = name

  try:

    value = source[name]

    if value is not None:

      # If the destination_name has one or more '.' in it

      # traverse the destination object downward to find

      # the actual destination object and property name

      parts = destination_name.split('.')

      for part in parts[0:-1]:

        destination = getattr(destination, part)

        destination_name = parts[-1]

      setattr(destination, destination_name, value)

  except KeyError:

    # source property not found

    pass

def NewStatusFromJsonDict(data):

  '''Create a new Status instance based on a JSON dict.

  Args:

    data: A JSON dict, as parsed from a twitter API response

  Returns:

    A Status instance

  '''

  status = twitter_pb2.Status()

  _CopyProperty(data, status, 'created_at')

  _CopyProperty(data, status, 'favorited')

  _CopyProperty(data, status, 'id')

  _CopyProperty(data, status, 'text')

  _CopyProperty(data, status, 'in_reply_to_screen_name')

  _CopyProperty(data, status, 'in_reply_to_user_id')

  _CopyProperty(data, status, 'in_reply_to_status_id')

  _CopyProperty(data, status, 'truncated')

  _CopyProperty(data, status, 'source')

  if 'user' in data:

    status.user.CopyFrom(NewUserFromJsonDict(data['user']))

  return status

def ComputeCreatedAtInSeconds(status):

  '''Returns the number of seconds past the epoch in the current timezone.

  Args:

    status: A status instance

  Returns:

    The number of seconds since the status was created.

  '''

  return calendar.timegm(rfc822.parsedate(status.created_at))

def ComputeRelativeCreatedAt(status, now=None):

  '''Get a human redable string representing the posting time

  Args:

    status: A status instance

    now: 

      The current time, if the client choses to set it.  Defaults 

      to the wall clock time.

  Returns:

    A human readable string representing the posting time

    '''

  if now is None:

    now = time.time()

  fudge = 1.25

  created_at_in_seconds = ComputeCreatedAtInSeconds(status)

  delta = int(now) - int(created_at_in_seconds)

  if delta < (1 * fudge):

    return 'about a second ago'

  elif delta < (60 * (1/fudge)):

    return 'about %d seconds ago' % (delta)

  elif delta < (60 * fudge):

    return 'about a minute ago'

  elif delta < (60 * 60 * (1/fudge)):

    return 'about %d minutes ago' % (delta / 60)

  elif delta < (60 * 60 * fudge):

    return 'about an hour ago'

  elif delta < (60 * 60 * 24 * (1/fudge)):

    return 'about %d hours ago' % (delta / (60 * 60))

  elif delta < (60 * 60 * 24 * fudge):

    return 'about a day ago'

  else:

    return 'about %d days ago' % (delta / (60 * 60 * 24))

def NewUserFromJsonDict(data):

  '''Create a new User instance based on a JSON dict.

  Args:

    data: A JSON dict, as parsed from a twitter API response

  Returns:

    A User instance

  '''

  user = twitter_pb2.User()

  _CopyProperty(data, user, 'id')

  _CopyProperty(data, user, 'name')

  _CopyProperty(data, user, 'screen_name')

  _CopyProperty(data, user, 'location')

  _CopyProperty(data, user, 'description')

  _CopyProperty(data, user, 'statuses_count')

  _CopyProperty(data, user, 'followers_count')

  _CopyProperty(data, user, 'favourites_count', 'favorites_count')

  _CopyProperty(data, user, 'friends_count')

  _CopyProperty(data, user, 'profile_image_url', 'profile.image_url')

  _CopyProperty(data, user, 'profile_background_tile', 'profile.background_tile')

  _CopyProperty(data, user, 'profile_background_image_url', 'profile.background_image_url')

  _CopyProperty(data, user, 'profile_sidebar_fill_color', 'profile.sidebar_fill_color')

  _CopyProperty(data, user, 'profile_background_color', 'profile.background_color')

  _CopyProperty(data, user, 'profile_link_color', 'profile.link_color')

  _CopyProperty(data, user, 'profile_text_color', 'profile.text_color')

  _CopyProperty(data, user, 'protected')

  _CopyProperty(data, user, 'utc_offset')

  _CopyProperty(data, user, 'time_zone')

  _CopyProperty(data, user, 'url')

  if 'status' in data:

    user.status.CopyFrom(NewStatusFromJsonDict(data['status']))

  return user

def NewDirectMessageFromJsonDict(data):

  '''Create a new DirectMessage instance based on a JSON dict.

  Args:

    data: A JSON dict, as parsed from a twitter API response

  Returns:

    A DirectMessage instance

  '''

  direct_message = twitter_pb2.DirectMessage()

  _CopyProperty(data, direct_message, 'created_at')

  _CopyProperty(data, direct_message, 'recipient_id')

  _CopyProperty(data, direct_message, 'sender_id')

  _CopyProperty(data, direct_message, 'text')

  _CopyProperty(data, direct_message, 'sender_screen_name')

  _CopyProperty(data, direct_message, 'id')

  _CopyProperty(data, direct_message, 'recipient_screen_name')

  return direct_message

def NewResultsFromJsonDict(data):

  '''Create a new Results instance based on a JSON dict.

  Args:

    data: A JSON dict, as parsed from a twitter API response

  Returns:

    A Results instance

  '''

  results = twitter_pb2.Results()

  _CopyProperty(data, results, 'completed_in')

  _CopyProperty(data, results, 'max_id')

  _CopyProperty(data, results, 'next_page')

  _CopyProperty(data, results, 'page')

  _CopyProperty(data, results, 'query')

  _CopyProperty(data, results, 'refresh_url')

  _CopyProperty(data, results, 'since_id')

  _CopyProperty(data, results, 'results_per_page')

  if 'results' in data:

    for result_data in data['results']:

      result = results.results.add()

      result.CopyFrom(NewResultFromJsonDict(result_data))

  return results

def NewResultFromJsonDict(data):

  '''Create a new Result instance based on a JSON dict.

  Args:

    data: A JSON dict, as parsed from a twitter API response

  Returns:

    A Result instance

  '''

  result = twitter_pb2.Results.Result()

  _CopyProperty(data, result, 'created_at')

  _CopyProperty(data, result, 'from_user')

  _CopyProperty(data, result, 'from_user_id')

  _CopyProperty(data, result, 'id')

  _CopyProperty(data, result, 'iso_language_code')

  _CopyProperty(data, result, 'profile_image_url')

  _CopyProperty(data, result, 'source')

  _CopyProperty(data, result, 'text')

  _CopyProperty(data, result, 'to_user')

  _CopyProperty(data, result, 'to_user_id')

  return result

class Api(object):

  '''A python interface into the Twitter API

  By default, the Api caches results for 1 minute.

  Example usage:

    To create an instance of the twitter.Api class, with no authentication:

      >>> import twitter

      >>> api = twitter.Api()

    To fetch the most recently posted public twitter status messages:

      >>> statuses = api.GetPublicTimeline()

      >>> print [s.user.name for s in statuses]

      [u'DeWitt', u'Kesuke Miyagi', u'ev', u'Buzz Andersen', u'Biz Stone'] #...

    To fetch a single user's public status messages, where "user" is either

    a Twitter "short name" or their user id.

      >>> statuses = api.GetUserTimeline(user)

      >>> print [s.text for s in statuses]

    To use authentication, instantiate the twitter.Api class with a

    username and password:

      >>> api = twitter.Api(username='twitter user', password='twitter pass')

    To fetch your friends (after being authenticated):

      >>> users = api.GetFriends()

      >>> print [u.name for u in users]

    To post a twitter status message (after being authenticated):

      >>> status = api.PostUpdate('I love python-twitter!')

      >>> print status.text

      I love python-twitter!

    There are many other methods, including:

      >>> api.PostUpdates(status)

      >>> api.PostDirectMessage(user, text)

      >>> api.GetUser(user)

      >>> api.GetReplies()

      >>> api.GetUserTimeline(user)

      >>> api.GetStatus(id)

      >>> api.DestroyStatus(id)

      >>> api.GetFriendsTimeline(user)

      >>> api.GetFriends(user)

      >>> api.GetFollowers()

      >>> api.GetFeatured()

      >>> api.GetDirectMessages()

      >>> api.PostDirectMessage(user, text)

      >>> api.DestroyDirectMessage(id)

      >>> api.DestroyFriendship(user)

      >>> api.CreateFriendship(user)

      >>> api.GetUserByEmail(email)

  '''

  DEFAULT_CACHE_TIMEOUT = 60 # cache for 1 minute

  _API_REALM = 'Twitter API'

  def __init__(self,

               username=None,

               password=None,

               input_encoding=None,

               request_headers=None):

    '''Instantiate a new twitter.Api object.

    Args:

      username: The username of the twitter account.  [optional]

      password: The password for the twitter account. [optional]

      input_encoding: The encoding used to encode input strings. [optional]

      request_header: A dictionary of additional HTTP request headers. [optional]

    '''

    self._cache = _FileCache()

    self._urllib = urllib2

    self._cache_timeout = Api.DEFAULT_CACHE_TIMEOUT

    self._InitializeRequestHeaders(request_headers)

    self._InitializeUserAgent()

    self._InitializeDefaultParameters()

    self._input_encoding = input_encoding

    self.SetCredentials(username, password)

  def GetPublicTimeline(self, since_id=None):

    '''Fetch the sequnce of public Status message for all users.

    Args:

      since_id:

        Returns only public statuses with an ID greater than (that is,

        more recent than) the specified ID. [Optional]

    Returns:

      An sequence of Status instances, one for each message

    '''

    parameters = {}

    if since_id:

      parameters['since_id'] = since_id

    url = 'http://twitter.com/statuses/public_timeline.json'

    json = self._FetchUrl(url,  parameters=parameters)

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return [NewStatusFromJsonDict(x) for x in data]

  def GetFriendsTimeline(self,

                         user=None,

                         count=None,

                         since=None, 

                         since_id=None):

    '''Fetch the sequence of Status messages for a user's friends

    The twitter.Api instance must be authenticated if the user is private.

    Args:

      user:

        Specifies the ID or screen name of the user for whom to return

        the friends_timeline.  If unspecified, the username and password

        must be set in the twitter.Api instance.  [Optional]

      count: 

        Specifies the number of statuses to retrieve. May not be

        greater than 200. [Optional]

      since:

        Narrows the returned results to just those statuses created

        after the specified HTTP-formatted date. [Optional]

      since_id:

        Returns only public statuses with an ID greater than (that is,

        more recent than) the specified ID. [Optional]

    Returns:

      A sequence of Status instances, one for each message

    '''

    if user:

      url = 'http://twitter.com/statuses/friends_timeline/%s.json' % user

    elif not user and not self._username:

      raise TwitterError("User must be specified if API is not authenticated.")

    else:

      url = 'http://twitter.com/statuses/friends_timeline.json'

    parameters = {}

    if count is not None:

      try:

        if int(count) > 200:

          raise TwitterError("'count' may not be greater than 200")

      except ValueError:

        raise TwitterError("'count' must be an integer")

      parameters['count'] = count

    if since:

      parameters['since'] = since

    if since_id:

      parameters['since_id'] = since_id

    json = self._FetchUrl(url, parameters=parameters)

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return [NewStatusFromJsonDict(x) for x in data]

  def GetUserTimeline(self, user=None, count=None, since=None, since_id=None):

    '''Fetch the sequence of public Status messages for a single user.

    The twitter.Api instance must be authenticated if the user is private.

    Args:

      user:

        either the username (short_name) or id of the user to retrieve.  If

        not specified, then the current authenticated user is used. [optional]

      count: the number of status messages to retrieve [optional]

      since:

        Narrows the returned results to just those statuses created

        after the specified HTTP-formatted date. [optional]

      since_id:

        Returns only public statuses with an ID greater than (that is,

        more recent than) the specified ID. [Optional]

    Returns:

      A sequence of Status instances, one for each message up to count

    '''

    try:

      if count:

        int(count)

    except:

      raise TwitterError("Count must be an integer")

    parameters = {}

    if count:

      parameters['count'] = count

    if since:

      parameters['since'] = since

    if since_id:

      parameters['since_id'] = since_id

    if user:

      url = 'http://twitter.com/statuses/user_timeline/%s.json' % user

    elif not user and not self._username:

      raise TwitterError("User must be specified if API is not authenticated.")

    else:

      url = 'http://twitter.com/statuses/user_timeline.json'

    json = self._FetchUrl(url, parameters=parameters)

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return [NewStatusFromJsonDict(x) for x in data]

  def GetStatus(self, id):

    '''Returns a single status message.

    The twitter.Api instance must be authenticated if the status message is private.

    Args:

      id: The numerical ID of the status you're trying to retrieve.

    Returns:

      A Status instance representing that status message

    '''

    try:

      if id:

        int(id)

    except:

      raise TwitterError("id must be an integer")

    url = 'http://twitter.com/statuses/show/%s.json' % id

    json = self._FetchUrl(url)

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return NewStatusFromJsonDict(data)

  def DestroyStatus(self, id):

    '''Destroys the status specified by the required ID parameter.

    The twitter.Api instance must be authenticated and thee

    authenticating user must be the author of the specified status.

    Args:

      id: The numerical ID of the status you're trying to destroy.

    Returns:

      A Status instance representing the destroyed status message

    '''

    try:

      if id:

        int(id)

    except:

      raise TwitterError("id must be an integer")

    url = 'http://twitter.com/statuses/destroy/%s.json' % id

    json = self._FetchUrl(url, post_data={})

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return NewStatusFromJsonDict(data)

  def PostUpdate(self, status, in_reply_to_status_id=None):

    '''Post a twitter status message from the authenticated user.

    The twitter.Api instance must be authenticated.

    Args:

      status:

        The message text to be posted.  Must be less than or equal to

        140 characters.

      in_reply_to_status_id:

        The ID of an existing status that the status to be posted is

        in reply to.  This implicitly sets the in_reply_to_user_id

        attribute of the resulting status to the user ID of the

        message being replied to.  Invalid/missing status IDs will be

        ignored. [Optional]

    Returns:

      A Status instance representing the message posted.

    '''

    if not self._username:

      raise TwitterError("The twitter.Api instance must be authenticated.")

    url = 'http://twitter.com/statuses/update.json'

    if len(status) > CHARACTER_LIMIT:

      raise TwitterError("Text must be less than or equal to %d characters. "

                         "Consider using PostUpdates." % CHARACTER_LIMIT)

    data = {'status': status}

    if in_reply_to_status_id:

      data['in_reply_to_status_id'] = in_reply_to_status_id

    json = self._FetchUrl(url, post_data=data)

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return NewStatusFromJsonDict(data)

  def PostUpdates(self, status, continuation=None, **kwargs):

    '''Post one or more twitter status messages from the authenticated user.

    Unlike api.PostUpdate, this method will post multiple status updates

    if the message is longer than 140 characters.

    The twitter.Api instance must be authenticated.

    Args:

      status:

        The message text to be posted.  May be longer than 140 characters.

      continuation:

        The character string, if any, to be appended to all but the

        last message.  Note that Twitter strips trailing '...' strings

        from messages.  Consider using the unicode \u2026 character

        (horizontal ellipsis) instead. [Defaults to None]

      **kwargs:

        See api.PostUpdate for a list of accepted parameters.

    Returns:

      A list of Status instances representing the messages posted.

    '''

    results = list()

    if continuation is None:

      continuation = ''

    line_length = CHARACTER_LIMIT - len(continuation)

    lines = textwrap.wrap(status, line_length)

    for line in lines[0:-1]:

      results.append(self.PostUpdate(line + continuation, **kwargs))

    results.append(self.PostUpdate(lines[-1], **kwargs))

    return results

  def GetReplies(self, since=None, since_id=None, page=None): 

    '''Get a sequence of status messages representing the 20 most recent

    replies (status updates prefixed with @username) to the authenticating

    user.

    Args:

      page: 

      since:

        Narrows the returned results to just those statuses created

        after the specified HTTP-formatted date. [optional]

      since_id:

        Returns only public statuses with an ID greater than (that is,

        more recent than) the specified ID. [Optional]

    Returns:

      A sequence of Status instances, one for each reply to the user.

    '''

    url = 'http://twitter.com/statuses/replies.json'

    if not self._username:

      raise TwitterError("The twitter.Api instance must be authenticated.")

    parameters = {}

    if since:

      parameters['since'] = since

    if since_id:

      parameters['since_id'] = since_id

    if page:

      parameters['page'] = page

    json = self._FetchUrl(url, parameters=parameters)

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return [NewStatusFromJsonDict(x) for x in data]

  def GetFriends(self, user=None, page=None):

    '''Fetch the sequence of twitter.User instances, one for each friend.

    Args:

      user: the username or id of the user whose friends you are fetching.  If

      not specified, defaults to the authenticated user. [optional]

    The twitter.Api instance must be authenticated.

    Returns:

      A sequence of twitter.User instances, one for each friend

    '''

    if not self._username:

      raise TwitterError("twitter.Api instance must be authenticated")

    if user:

      url = 'http://twitter.com/statuses/friends/%s.json' % user 

    else:

      url = 'http://twitter.com/statuses/friends.json'

    parameters = {}

    if page:

      parameters['page'] = page

    json = self._FetchUrl(url, parameters=parameters)

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return [NewUserFromJsonDict(x) for x in data]

  def GetFollowers(self, page=None):

    '''Fetch the sequence of twitter.User instances, one for each follower

    The twitter.Api instance must be authenticated.

    Returns:

      A sequence of twitter.User instances, one for each follower

    '''

    if not self._username:

      raise TwitterError("twitter.Api instance must be authenticated")

    url = 'http://twitter.com/statuses/followers.json'

    parameters = {}

    if page:

      parameters['page'] = page

    json = self._FetchUrl(url, parameters=parameters)

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return [NewUserFromJsonDict(x) for x in data]

  def GetFeatured(self):

    '''Fetch the sequence of twitter.User instances featured on twitter.com

    The twitter.Api instance must be authenticated.

    Returns:

      A sequence of twitter.User instances

    '''

    url = 'http://twitter.com/statuses/featured.json'

    json = self._FetchUrl(url)

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return [NewUserFromJsonDict(x) for x in data]

  def GetUser(self, user):

    '''Returns a single user.

    The twitter.Api instance must be authenticated.

    Args:

      user: The username or id of the user to retrieve.

    Returns:

      A twitter.User instance representing that user

    '''

    url = 'http://twitter.com/users/show/%s.json' % user

    json = self._FetchUrl(url)

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return NewUserFromJsonDict(data)

  def GetDirectMessages(self, since=None, since_id=None, page=None):

    '''Returns a list of the direct messages sent to the authenticating user.

    The twitter.Api instance must be authenticated.

    Args:

      since:

        Narrows the returned results to just those statuses created

        after the specified HTTP-formatted date. [optional]

      since_id:

        Returns only public statuses with an ID greater than (that is,

        more recent than) the specified ID. [Optional]

    Returns:

      A sequence of twitter.DirectMessage instances

    '''

    url = 'http://twitter.com/direct_messages.json'

    if not self._username:

      raise TwitterError("The twitter.Api instance must be authenticated.")

    parameters = {}

    if since:

      parameters['since'] = since

    if since_id:

      parameters['since_id'] = since_id

    if page:

      parameters['page'] = page 

    json = self._FetchUrl(url, parameters=parameters)

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return [NewDirectMessageFromJsonDict(x) for x in data]

  def PostDirectMessage(self, user, text):

    '''Post a twitter direct message from the authenticated user

    The twitter.Api instance must be authenticated.

    Args:

      user: The ID or screen name of the recipient user.

      text: The message text to be posted.  Must be less than 140 characters.

    Returns:

      A twitter.DirectMessage instance representing the message posted

    '''

    if not self._username:

      raise TwitterError("The twitter.Api instance must be authenticated.")

    url = 'http://twitter.com/direct_messages/new.json'

    data = {'text': text, 'user': user}

    json = self._FetchUrl(url, post_data=data)

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return NewDirectMessageFromJsonDict(data)

  def DestroyDirectMessage(self, id):

    '''Destroys the direct message specified in the required ID parameter.

    The twitter.Api instance must be authenticated, and the

    authenticating user must be the recipient of the specified direct

    message.

    Args:

      id: The id of the direct message to be destroyed

    Returns:

      A twitter.DirectMessage instance representing the message destroyed

    '''

    url = 'http://twitter.com/direct_messages/destroy/%s.json' % id

    json = self._FetchUrl(url, post_data={})

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return NewDirectMessageFromJsonDict(data)

  def CreateFriendship(self, user):

    '''Befriends the user specified in the user parameter as the authenticating user.

    The twitter.Api instance must be authenticated.

    Args:

      The ID or screen name of the user to befriend.

    Returns:

      A twitter.User instance representing the befriended user.

    '''

    url = 'http://twitter.com/friendships/create/%s.json' % user

    json = self._FetchUrl(url, post_data={})

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return NewUserFromJsonDict(data)

  def DestroyFriendship(self, user):

    '''Discontinues friendship with the user specified in the user parameter.

    The twitter.Api instance must be authenticated.

    Args:

      The ID or screen name of the user  with whom to discontinue friendship.

    Returns:

      A twitter.User instance representing the discontinued friend.

    '''

    url = 'http://twitter.com/friendships/destroy/%s.json' % user

    json = self._FetchUrl(url, post_data={})

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return NewUserFromJsonDict(data)

  def CreateFavorite(self, status):

    '''Favorites the status specified in the status parameter as the authenticating user.

    Returns the favorite status when successful.

    The twitter.Api instance must be authenticated.

    Args:

      The Status instance to mark as a favorite.

    Returns:

      A Status instance representing the newly-marked favorite.

    '''

    url = 'http://twitter.com/favorites/create/%s.json' % status.id

    json = self._FetchUrl(url, post_data={})

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return NewStatusFromJsonDict(data)

  def DestroyFavorite(self, status):

    '''Un-favorites the status specified in the ID parameter as the authenticating user.

    Returns the un-favorited status in the requested format when successful.

    The twitter.Api instance must be authenticated.

    Args:

      The Status to unmark as a favorite.

    Returns:

      A Status instance representing the newly-unmarked favorite.

    '''

    url = 'http://twitter.com/favorites/destroy/%s.json' % status.id

    json = self._FetchUrl(url, post_data={})

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return NewStatusFromJsonDict(data)

  def GetUserByEmail(self, email):

    '''Returns a single user by email address.

    Args:

      email: The email of the user to retrieve.

    Returns:

      A twitter.User instance representing that user

    '''

    url = 'http://twitter.com/users/show.json?email=%s' % email

    json = self._FetchUrl(url)

    data = simplejson.loads(json)

    self._CheckForTwitterError(data)

    return NewUserFromJsonDict(data)

  def SetCredentials(self, username, password):

    '''Set the username and password for this instance

    Args:

      username: The twitter username.

      password: The twitter password.

    '''

    self._username = username

    self._password = password

  def ClearCredentials(self):

    '''Clear the username and password for this instance

    '''

    self._username = None

    self._password = None

  def SetCache(self, cache):

    '''Override the default cache.  Set to None to prevent caching.

    Args:

      cache: an instance that supports the same API as the  twitter._FileCache

    '''

    self._cache = cache

  def SetUrllib(self, urllib):

    '''Override the default urllib implementation.

    Args:

      urllib: an instance that supports the same API as the urllib2 module

    '''

    self._urllib = urllib

  def SetCacheTimeout(self, cache_timeout):

    '''Override the default cache timeout.

    Args:

      cache_timeout: time, in seconds, that responses should be reused.

    '''

    self._cache_timeout = cache_timeout

  def SetUserAgent(self, user_agent):

    '''Override the default user agent

    Args:

      user_agent: a string that should be send to the server as the User-agent

    '''

    self._request_headers['User-Agent'] = user_agent