title: What do double underscores indicate?
body: <p>In Python I know that double underscores preceding a name cause Python to prepend the <code>classname</code> to the <code>variable</code> name as in <code>_classname__variable</code> name (name mangling). So my question is this, in an Python/Django app I have been asked to modify, there are variable(?) names of the type <code>tr_rowid_debtor__de_listed_date__lte</code> . Is this three variables (<code>tr_rowid_debtor</code>, <code>de_listed_date</code> and <code>lte</code>) or is this some special construct for Python? It is occurring in a statement that builds a query string for Django ... </p>
  
  <pre><code>query = DeTransaction.objects.select_related().filter(
      tr_rowid_debtor__de_listed_date__lte=to_date,
      tr_rowid_debtor__de_rowid_client__cl_rowid=in_client
  ).values(
      'tr_rowid_debtor','tr_rowid_debtor__de_listed_date',
      'tr_payment_date','tr_account','tr_to_agency','tr_to_client'
  )
  </code></pre>
  
  <p>Any advice here would be appreciated.</p>