Here is a quick example on how to use it for retrieving and parsing and XRD document:
from pydataportability.xrd.parser import parse_xrd
fp = open('xrdfile.xrd','r')
resource = parse_xrd(fp)
fp.close()
Of course you can also retrieve such a file via urlopen or similar methods. What you need is a file pointer though.
Now that it’s parsed you can access the elements of the resource:
print resource.subject
print resource.type
print resource.expires # is a datetime object
print resource.aliases # will return a list of URIs
You can also access the links pointing to other resources which are stored in the links attribute. You can use the get_by_rel() in order to filter for the relationship types you are interested in
rels = resources.links.get_by_rel("describedby")
Moreover you can use the filter() method if you want advanced filtering:
rels = resources.links.filter(rels=['describedby','webfinger'],
media_types=['application/xml+xrd'])
This example will filter out all relationships which do not have the types describedby and webfinger together and additionally are of the type application/xml+xrd. So all these conditions are used as AND.
Now that you eventually have found some relationships you can access their attributes:
print link.uris # a list of URI strings.
print link.media_types # a list of media types for this relationship
print link.subject # None or string
print link.priority # integers
print link.templates # this is a list if URI template objects