title: python 3 can't concat bytes to str for a list
body: <p>I have the following chunk of code that I'm trying to run</p>
  
  <pre><code>import json
  import textProcess as tp
  
  review = open('../inres_review.json')
  vocabulary = open('../vocabulary.txt','w+')
  label = open('../label.txt','w+')
  data = open('../data.txt','w+')
  
  voc = []
  revs = []
  lab = []
  dat = []
  i=1
  for line in review:
      jre = json.loads(line)
      jstar = jre['stars']  
      text = jre['text']  
      lab.append(jstar)
      ws = tp.removeStopPunc(text)
      revs.append(ws)
      voc += ws
      i += 1
  
  for i in lab:
      label.write(str(i)+"\n")
  print ("label created successfully!")
  
  voc = list(set(voc))
  print (len(voc))
  print (type(i))
  for i in voc:
      vocabulary.write(i.encode('UTF-8')+"\n")
  print ("Vocabulary created successfully!")
  
  for revid, rev in enumerate(revs):
      dat.append({})
      for w in rev:
          if w in voca:
              k = voca.index(w)+1
              if k not in dat[revid]:
                  dat[revid][k] = 1
              else:
                  dat[revid][k] += 1
  print (len(revs))
  
  
  for revid, rev in enumerate(dat):
      for k,v in rev.iteritems():
          s = str(revid+1)+' '+str(k)+' '+str(v)+'\n'
          data.write(s)
  print ("successfully create data")
  
  
  review.close()
  vocabulary.close()
  label.close()
  data.close()
  </code></pre>
  
  <p>However, no matter what I changes I implement I am getting the following error. Can anyone please point out what's wrong here?</p>
  
  <pre><code>TypeError                                 Traceback (most recent call last)
  &lt;ipython-input-18-21a3dc9eb8ad&gt; in &lt;module&gt;()
       33 print (type(i))
       34 for i in bvoca:
  ---&gt; 35         vocabulary.write(i.encode('UTF-8')+"\n")
       36 print ("successfully create vocabulary!")
       37 
  
  TypeError: can't concat bytes to str
  </code></pre>
  
  <p>Any help is appreciated!</p>