title: How to use TaggedDocument in gensim?
body: <p>I have two directories from which I want to read their text files and label them, but I don't know how to do this via <code>TaggedDocument</code>. I thought it would work as TaggedDocument([Strings],[Labels]) but this doesn't work apparently. </p>
  
  <p>This is my code: </p>
  
  <pre><code>from gensim import models
  from gensim.models.doc2vec import TaggedDocument
  import utilities as util
  import os
  from sklearn import svm
  from nltk.tokenize import sent_tokenize
  CogPath = "./FixedCog/"
  NotCogPath = "./FixedNotCog/"
  SamplePath ="./Sample/"
  docs = []
  tags = []
  CogList = [p for p in os.listdir(CogPath) if p.endswith('.txt')]
  NotCogList = [p for p in os.listdir(NotCogPath) if p.endswith('.txt')]
  SampleList = [p for p in os.listdir(SamplePath) if p.endswith('.txt')]
  for doc in CogList:
       str = open(CogPath+doc,'r').read().decode("utf-8")
       docs.append(str)
       print docs
       tags.append(doc)
       print "###########"
       print tags
       print "!!!!!!!!!!!"
  for doc in NotCogList:
       str = open(NotCogPath+doc,'r').read().decode("utf-8")
       docs.append(str)
       tags.append(doc)
  for doc in SampleList:
       str = open(SamplePath + doc, 'r').read().decode("utf-8")
       docs.append(str)
       tags.append(doc)
  
  T = TaggedDocument(docs,tags)
  
  model = models.Doc2Vec(T,alpha=.025, min_alpha=.025, min_count=1,size=50)
  </code></pre>
  
  <p>and this is the error I get: </p>
  
  <pre><code>Traceback (most recent call last):
    File "/home/farhood/PycharmProjects/word2vec_prj/doc2vec.py", line 34, in &lt;module&gt;
      model = models.Doc2Vec(T,alpha=.025, min_alpha=.025, min_count=1,size=50)
    File "/home/farhood/anaconda2/lib/python2.7/site-packages/gensim/models/doc2vec.py", line 635, in __init__
      self.build_vocab(documents, trim_rule=trim_rule)
    File "/home/farhood/anaconda2/lib/python2.7/site-packages/gensim/models/word2vec.py", line 544, in build_vocab
      self.scan_vocab(sentences, progress_per=progress_per, trim_rule=trim_rule)  # initial survey
    File "/home/farhood/anaconda2/lib/python2.7/site-packages/gensim/models/doc2vec.py", line 674, in scan_vocab
      if isinstance(document.words, string_types):
  AttributeError: 'list' object has no attribute 'words'
  </code></pre>