title: Is it safe to mix readline() and line iterators in python file processing?
body: <p>Is it safe to read some lines with <code>readline()</code> and also use <code>for line in file</code>, and is it guaranteed to use the same file position?</p>
  
  <p>Usually, I want to disregard the first line (headers), so I do this:</p>
  
  <pre><code>FI = open("myfile.txt")
  FI.readline()             # disregard the first line
  for line in FI:
      my_process(line)
  FI.close()
  </code></pre>
  
  <p>Is this safe, i.e., is it guaranteed that the same file position variable is used while iterating lines?</p>