title: Parameters with leading underscores in Python suds
body: <p>I am working with a SOAP service that has a variable defined with leading underscores (one would assume private, but the documentation has specific examples where one must use them). In the WSDL it looks like this:</p>
  
  <pre><code>&lt;xsd:element maxOccurs="1" minOccurs="0" name="__encoded_query" type="xsd:string"/&gt;
  </code></pre>
  
  <p>Through some experimentation I have determined that, using named parameters in my client.service calls I am able to assign variables as normal, except for ones which have the leading underscore.</p>
  
  <p>For example:</p>
  
  <pre><code>client.service.getRecords( name='server1' )
  </code></pre>
  
  <p>Produces the correct XML:</p>
  
  <pre><code>&lt;ns1:getRecords&gt;
    &lt;name&gt;server1&lt;/name&gt;
  &lt;/ns1:getRecords&gt;
  </code></pre>
  
  <p>but if I attempt to use the parameter with the underscore:</p>
  
  <pre><code>client.service.getRecords( __encoded_query='name=server1' )
  </code></pre>
  
  <p>the XML which is produced does not include the parameter at all:</p>
  
  <pre><code>&lt;ns1:getRecords/&gt;
  </code></pre>
  
  <p>I am not sure whether this is a syntax nuance that I am unfamiliar with (either Python or suds) or perhaps suds attempting to be "smart" by protecting the variables based on the private variable convention. In any case, this is the documented way to use this web service so I need to figure out how to get suds to produce the XML including the <code>__encoded_query</code> block.</p>