validate xml file against different schemas

Hi,
I am pretty new to python/xml and need some help. I am trying to parse an xml file and validate it against schema. I did parsed the file but have no idea how to validate it using schema, because I need to validate the xml file using 3 to 4 different schemas (.xsd files). In my xml file different parts needs to be validated using different schema files. Every xml ELEMEN_NODE is validated using different schema.How should I get arround this Any help is appreciated a small example will help alot. Thanks