what exactly the python's file.flush() is doing?
<p>hello everyone I found this in spec of python:</p>

<blockquote>
  <p>flush() does not necessarily write the file’s data to disk. Use flush() followed by os.fsync() to ensure this behavior.</p>
</blockquote>

<p>so my question is what exactly the python's flush is doing I thought that it forces to write data to the disk, but now I see that it doesn't why? thanks in advance</p>
