text: """Functions for Github authorisation."""
  from __future__ import print_function
  
  try:
      input = raw_input
  except NameError:
      pass
  
  import os
  
  import requests
  import getpass
  import json
  
  # Keyring stores passwords by a 'username', but we're not storing a username and
  # password
  fake_username = 'networkx-tests'
  
  class Obj(dict):
      """Dictionary with attribute access to names."""
      def __getattr__(self, name):
          try:
              return self[name]
          except KeyError:
              raise AttributeError(name)
      
      def __setattr__(self, name, val):
          self[name] = val
  
  token = None
  def get_auth_token():
      global token
      
      if token is not None:
          return token
      
      import keyring
      token = keyring.get_password('github', fake_username)
      if token is not None:
          return token
      
      print("Please enter your github username and password. These are not "
             "stored, only used to get an oAuth token. You can revoke this at "
             "any time on Github.")
      user = input("Username: ")
      pw = getpass.getpass("Password: ")
      
      auth_request = {
        "scopes": [
          "public_repo",
          "gist"
        ],
        "note": "NetworkX tools",
        "note_url": "https://github.com/networkx/networkx/tree/master/tools",
      }
      response = requests.post('https://api.github.com/authorizations',
                              auth=(user, pw), data=json.dumps(auth_request))
      response.raise_for_status()
      token = json.loads(response.text)['token']
      keyring.set_password('github', fake_username, token)
      return token
  
  def make_auth_header():
      return {'Authorization': 'token ' + get_auth_token()}
  
  def post_issue_comment(project, num, body):
      url = 'https://api.github.com/repos/{project}/issues/{num}/comments'.format(project=project, num=num)
      payload = json.dumps({'body': body})
      r = requests.post(url, data=payload, headers=make_auth_header())
  
  def post_gist(content, description='', filename='file', auth=False):
      """Post some text to a Gist, and return the URL."""
      post_data = json.dumps({
        "description": description,
        "public": True,
        "files": {
          filename: {
            "content": content
          }
        }
      }).encode('utf-8')
      
      headers = make_auth_header() if auth else {}
      response = requests.post("https://api.github.com/gists", data=post_data, headers=headers)
      response.raise_for_status()
      response_data = json.loads(response.text)
      return response_data['html_url']
      
  def get_pull_request(project, num):
      """get pull request info  by number
      """
      url = "https://api.github.com/repos/{project}/pulls/{num}".format(project=project, num=num)
      response = requests.get(url)
      response.raise_for_status()
      return json.loads(response.text, object_hook=Obj)
  
  def get_pulls_list(project):
      """get pull request list
      """
      url = "https://api.github.com/repos/{project}/pulls".format(project=project)
      response = requests.get(url)
      response.raise_for_status()
      return json.loads(response.text)
  
  # encode_multipart_formdata is from urllib3.filepost
  # The only change is to iter_fields, to enforce S3's required key ordering
  
  def iter_fields(fields):
      fields = fields.copy()
      for key in ('key', 'acl', 'Filename', 'success_action_status', 'AWSAccessKeyId',
          'Policy', 'Signature', 'Content-Type', 'file'):
          yield (key, fields.pop(key))
      for (k,v) in fields.items():
          yield k,v
  
  def encode_multipart_formdata(fields, boundary=None):
      """
      Encode a dictionary of `fields` using the multipart/form-data mime format.
  
      :param fields:
          Dictionary of fields or list of (key, value) field tuples.  The key is
          treated as the field name, and the value as the body of the form-data
          bytes. If the value is a tuple of two elements, then the first element
          is treated as the filename of the form-data section.
  
          Field names and filenames must be unicode.
  
      :param boundary:
          If not specified, then a random boundary will be generated using
          :func:`mimetools.choose_boundary`.
      """
      # copy requests imports in here:
      from io import BytesIO
      from requests.packages.urllib3.filepost import (
          choose_boundary, six, writer, b, get_content_type
      )
      body = BytesIO()
      if boundary is None:
          boundary = choose_boundary()
  
      for fieldname, value in iter_fields(fields):
          body.write(b('--%s\r\n' % (boundary)))
  
          if isinstance(value, tuple):
              filename, data = value
              writer(body).write('Content-Disposition: form-data; name="%s"; '
                                 'filename="%s"\r\n' % (fieldname, filename))
              body.write(b('Content-Type: %s\r\n\r\n' %
                         (get_content_type(filename))))
          else:
              data = value
              writer(body).write('Content-Disposition: form-data; name="%s"\r\n'
                                 % (fieldname))
              body.write(b'Content-Type: text/plain\r\n\r\n')
  
          if isinstance(data, int):
              data = str(data)  # Backwards compatibility
          if isinstance(data, six.text_type):
              writer(body).write(data)
          else:
              body.write(data)
  
          body.write(b'\r\n')
  
      body.write(b('--%s--\r\n' % (boundary)))
  
      content_type = b('multipart/form-data; boundary=%s' % boundary)
  
      return body.getvalue(), content_type
  
  
  def post_download(project, filename, name=None, description=""):
      """Upload a file to the GitHub downloads area"""
      if name is None:
          name = os.path.basename(filename)
      with open(filename, 'rb') as f:
          filedata = f.read()
      
      url = "https://api.github.com/repos/{project}/downloads".format(project=project)
      
      payload = json.dumps(dict(name=name, size=len(filedata),
                      description=description))
      response = requests.post(url, data=payload, headers=make_auth_header())
      response.raise_for_status()
      reply = json.loads(response.content)
      s3_url = reply['s3_url']
      
      fields = dict(
          key=reply['path'],
          acl=reply['acl'],
          success_action_status=201,
          Filename=reply['name'],
          AWSAccessKeyId=reply['accesskeyid'],
          Policy=reply['policy'],
          Signature=reply['signature'],
          file=(reply['name'], filedata),
      )
      fields['Content-Type'] = reply['mime_type']
      data, content_type = encode_multipart_formdata(fields)
      s3r = requests.post(s3_url, data=data, headers={'Content-Type': content_type})
      return s3r
  