title: python call command line with Chinese Characters in windows fails
body: <p>Under python in windows, <strong>in py script (test.py)</strong>, os.system or subprocess.Popen calling the dos command fails, but succeeds under <strong>command line (windows->cmd.exe)</strong>, the script is as the following
  additional info:
  <li>1. the dos (windows->cmd.exe) encoding is 'cp936', belonging to 'gbk'</li>
  <li>2. I have decoded the test.py into utf-8 by notepad++</li>
  <li>3 .decode('gbk'), .encode('gbk'), .decode('utf-8'), .enode('utf-8') have been tried</li>
  <li>4. I do not know why</li>
  Error information: </p>
  
  <pre><code>    C:\Python27\python.exe E:/XtTradeClient/test.py
      File "E:/XtTradeClient/test.py", line 5 
      SyntaxError: Non-ASCII character '\xba' in file E:/XtTradeClient/test.py on line 5,but no encoding declared; see http://www.python.org/peps/pep-0263.html for details
  
      Process finished with exit code 1
  
      -------------------------------------------------------------------------------
      # encoding='utf-8'
      import os
  
      if __name__ == "__main__":
          info = '汉字'
          cmd = 'echo ' + info
          if 0 != os.system(cmd):
              raise Exception('failed to call 'echo in command')
      -------------------------------------------------------------------------------
  </code></pre>