title: What does it mean "weakly-referenced object no longer exists"?
body: <p>I am running a Python code and I get the following error message:</p>
  
  <pre><code>Exception exceptions.ReferenceError: 'weakly-referenced object no longer exists' in &lt;bound method crawler.__del__ of &lt;searchengine.crawler instance at 0x2b8c1f99ef80&gt;&gt; ignored
  </code></pre>
  
  <p>Does anybody know what can it means?</p>
  
  <p>P.S.
  This is the code which produce the error:</p>
  
  <pre><code>import sqlite
  
  class crawler:
  
    def __init__(self,dbname):
      tmp = sqlite.connect(dbname)
      self.con = tmp.cursor()
  
    def __del__(self):
      self.con.close()
  
  crawler =  crawler('searchindex.db')
  </code></pre>