title: Why won't unicodecsv write properly?
body: <p>I have the following Python code:</p>
  
  <pre><code>import unicodecsv as csv
  import sys
  
  with open("unicode_test.csv", "w+b") as csv_file:
      writer = csv.writer(csv_file, encoding="utf-8")
      writer.writerow([u'\xe3\x81\x93\xe3\x82\x93\xe3\x81\xab\xe3\x81\xa1\xe3\x81\xaf\xe4\xb8\x96\xe7\x95\x8c'])
  </code></pre>
  
  <p>This should create a CSV that says "こんにちは世界"; instead, it writes gibberish. Inspecting the end product with a hex editor shows similarities: EX YY ZZ gets converted to C3 AX C2 YY C2 ZZ, though I can't fathom how.</p>
  
  <p>I am running Python 2.7.11 on Windows 10, and sys.stdout.encoding says "cp437" in the console.</p>