title: how to use python help to file functions
body: <p>If I want to see the <code>str.replace()</code> function: <code>help(str.replace)</code>
  the result is:</p>
  
  <pre><code>Help on method_descriptor:
  
  replace(...)
      S.replace(old, new[, count]) -&gt; str
  
      Return a copy of S with all occurrences of substring
      old replaced by new.  If the optional argument count is
      given, only the first count occurrences are replaced.
  (END)
  </code></pre>
  
  <p>but how use help <code>file.read</code> or <code>readlines</code>?
  for example, <code>help(file.read)</code> and <code>help(read)</code> are both errors:</p>
  
  <pre><code>&gt;&gt;&gt; help(file)
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  NameError: name 'file' is not defined
  &gt;&gt;&gt; help(file.read)
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  NameError: name 'file' is not defined
  &gt;&gt;&gt; help(read)
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  NameError: name 'read' is not defined
  </code></pre>
  
  <p>How can I use help see file functions?</p>