title: ValueError: too many values to unpack for zip of python2.7
body: <p>I want to show documents and words of doc2vec model with t-SNE in different color. I wrote the following code in python2.7. But I got error. I have not used t-SNE and plot in python till now.</p>
  
  <pre><code>modelfile='/home/fl/models/Robust/dimention500/my_model.doc2vec'
  wordNum=10000
  docNum=1000
  words_vec = []
  words_label = []
  docs_vec = []
  docs_label = []
  all_vec = []
  
  model = gensim.models.Doc2Vec.load(modelfile)
  w2v = model.wv.vocab
  d2v = model.docvecs
  
  lengthVoc=len(w2v)
  ids=[None]*wordNum
  for i in range(10000):
      ids[i]=random.randint(1,lengthVoc)
  for i, word in enumerate(w2v.keys()):
      if i in ids:
              all_vec.append(model[word])
              words_vec.append(model[word])    
  for j, doc in enumerate(d2v.doctags.keys()):
      if j in docids:
              all_vec.append(d2v[doc])
              docs_vec.append(d2v[doc])
  
  words = TSNE(n_components=2).fit_transform(numpy.array(words_vec))
  docs = TSNE(n_components=2).fit_transform(numpy.array(docs_vec))
  all_dw = TSNE(n_components=2).fit_transform(numpy.array(all_vec))
  
  
  g1=words
  g2=docs
  data = (g1, g2)
  colors = ("red", "blue")
  groups = ("word", "document") 
  
  for data, color, group in zip(data, colors, groups):
      x, y = data
      plt.scatter(x, y, c=color, edgecolors='none', label=group)     
  plt.title('Robust04')
  plt.legend(loc=2)
  plt.show()
  </code></pre>
  
  <p>I got this error:</p>
  
  <pre><code>Traceback (most recent call last):
  File "test.py", line 91, in &lt;module&gt;
  x, y = data
  ValueError: too many values to unpack
  </code></pre>
  
  <p>When I changed the following part of my code to <code>plt.scatter(all_dw[:, 0], all_dw[:, 1])</code>, it shows the figure but all words and documents have same color.</p>
  
  <pre><code>for data, color, group in zip(data, colors, groups):
      x, y = data
      plt.scatter(x, y, c=color, edgecolors='none', label=group)
  </code></pre>