class_docstr: Objects of this class describe a single source of articles.
  
  A source is an abstraction over where the documents reside (the findArticles()
  method), how to retrieve their fulltexts, their metadata, how to tokenize the
  articles and how to normalize the tokens.
  
  What is NOT abstracted away (ie. must hold for all sources) is the idea of
  article identifiers (URIs), which uniquely identify each article within
  one source.
  
  This class is just an ABC interface; see eg. DmlSource or ArxmlivSource classes
  for concrete instances.
class_docstr_tok: ["Objects","of","this","class","describe","a","single","source","of","articles",".","A","source","is","an","abstraction","over","where","the","documents","reside","(","the","findArticles","(",")","method",")",",","how","to","retrieve","their","fulltexts",",","their","metadata",",","how","to","tokenize","the","articles","and","how","to","normalize","the","tokens",".","What","is","NOT","abstracted","away","(","ie",".","must","hold","for","all","sources",")","is","the","idea","of","article","identifiers","(","URIs",")",",","which","uniquely","identify","each","article","within","one","source",".","This","class","is","just","an","ABC","interface",";","see","eg",".","DmlSource","or","ArxmlivSource","classes","for","concrete","instances","."]
code: def __str__(self):
      return self.sourceId
  
imports: import logging
  import os
  import os.path
  import re
  import xml.sax
  from gensim import utils
  import sys
label_desc: Use image node_id 2 for calling the ArticleSource obj's underlying member method code with example usage: obj.__str__() and returns: self