A simple google search brings this: http://pyxb.sourceforge.net/userref_pyxbgen.html#pyxbgen
In particular the part that says:
Translate this into Python with the following command:
pyxbgen -u po1.xsd -m po1
The -u parameter identifies a schema document describing contents of a namespace. The parameter may be a path to a file on the local system, or a URL to a network-accessible location like http://www.weather.gov/forecasts/xml/DWMLgen/schema/DWML.xsd. The -m parameter specifies the name to be used by the Python module holding the bindings generated for the namespace in the preceding schema. After running this, the Python bindings will be in a file named po1.py.
EDIT Following your update:
Now that you have your generated Address
class and all the associated helpers, look at http://pyxb.sourceforge.net/userref_usebind.html in order to learn how to use them. For your specific question, you want to study the "Creating Instances in Python Code" paragraph. Basically to generate XML from your application data you simply do:
import example
address = Address()
address.FullName = "Jo La Banane"
# fill other members of address
# ...
with open('myoutput.xml', 'w') as file
f.write(address.toxml("utf-8"))
Now it's up to you to be curious and read the code being generated, pyxb's doc, call the various generated methods and experiment!