title: What does windows error 0 "ERROR_SUCCESS" mean?
body: <p>I've written a python program which read a stdout of another process by the pipe redirection.
  However, the program sucks in this line:</p>
  
  <pre><code>print "[Input Thread] ", self.inputPipe.readline(ii)
  </code></pre>
  
  <p>The error is IOError: [Errno 0] Error</p>
  
  <p>I found the explanation of windows errno 0. It makes confused because it defined as:</p>
  
  <blockquote>
    <p>The operation completed successfully.</p>
  </blockquote>
  
  <p>Why does an operation completed successfully lead to an error?</p>