Sending array parameter to web service method

Question

I've a PHP SOAP web service method using Yii, here's the code:

    /**
     * return list of cities
     * @param array $attributes filter for City
     * @return array
     * @soap
     */
    public function getCities($attributes=array()) {
        $result = City::model()->findAllByAttributes($attributes);
        return CJSON::decode(CJSON::encode($result));
    }

and how to send the $attributes parameter using Python as client ? I'm using SOAPpy, and this is my current code without $attribute parameter:

from SOAPpy import WSDL

WSDLURL = 'http://yii-soap.lan/service'
server = WSDL.Proxy(WSDLURL)
print server.getCities()