old_contents: # coding: utf-8
  
  from os.path import join
  from httplib import HTTPConnection, OK
  from pyquery import PyQuery
  
  
  class RequestError(StandardError):
      pass
  
  
  class HtmlSource(object):
      HOST = 'mosecom.ru'
      USER_AGENT = ('Mozilla/5.0 (Windows NT 6.1; WOW64; rv:30.0) Gecko/20100101 '
                    'Firefox/30.0')
      ENCODING = 'windows-1251'
      BASE_URL = '/air/air-today/'
      STATION_URL_PREFIX = '/air/air-today/station/'
      TABLE = 'table.html'
  
      def __init__(self, host=None, user_agent=None):
          self.headers = {'User-Agent': user_agent or self.USER_AGENT}
          self.__connection = HTTPConnection(host or self.HOST)
  
      def request(self, url):
          self.__connection.request('GET', url, headers=self.headers)
          response = self.__connection.getresponse()
          if response.status != OK:
              raise RequestError('reason=[request error] url=[%s] status=[%d]'
                                 % (url, response.status))
          return response.read()
  
      def get_stations_list(self):
          response = self.request(self.BASE_URL).decode(self.ENCODING)
          return list(PyQuery(response)('a')
                      .map(lambda i, v: PyQuery(v).attr('href'))
                      .filter(lambda i, v: v.startswith(self.STATION_URL_PREFIX))
                      .map(lambda i, v: v.replace(self.STATION_URL_PREFIX, '')))
  
      def get_station_html(self, station):
          return self.request(join(self.STATION_URL_PREFIX, station, self.TABLE))
  
new_contents: # coding: utf-8
  
  from os.path import join
  from httplib import HTTPConnection, OK
  from pyquery import PyQuery
  
  
  class RequestError(StandardError):
      pass
  
  
  class HtmlSource(object):
      HOST = 'mosecom.ru'
      USER_AGENT = ('Mozilla/5.0 (Windows NT 6.1; WOW64; rv:30.0) Gecko/20100101 '
                    'Firefox/30.0')
      ENCODING = 'windows-1251'
      BASE_URL = '/air/air-today/'
      STATION_URL_PREFIX = '/air/air-today/station/'
      TABLE = 'table.html'
  
      def __init__(self, host=None, user_agent=None):
          self.headers = {'User-Agent': (user_agent if user_agent is not None
                                         else self.USER_AGENT)}
          self.__connection = HTTPConnection(host if host is not None
                                             else self.HOST)
  
      def request(self, url):
          self.__connection.request('GET', url, headers=self.headers)
          response = self.__connection.getresponse()
          if response.status != OK:
              raise RequestError('reason=[request error] url=[%s] status=[%d]'
                                 % (url, response.status))
          return response.read()
  
      def get_stations_list(self):
          response = self.request(self.BASE_URL).decode(self.ENCODING)
          return list(PyQuery(response)('a')
                      .map(lambda i, v: PyQuery(v).attr('href'))
                      .filter(lambda i, v: v.startswith(self.STATION_URL_PREFIX))
                      .map(lambda i, v: v.replace(self.STATION_URL_PREFIX, '')))
  
      def get_station_html(self, station):
          return self.request(join(self.STATION_URL_PREFIX, station, self.TABLE))
  
subject: Fix ignoring empty str args value