import Foundation
import pprint

data = {'key': b'value' * 200}
for x in range(100):
    data = [data]

pprint.pprint(data)

data, err = Foundation.NSPropertyListSerialization.dataFromPropertyList_format_errorDescription_(
        data, Foundation.NSPropertyListXMLFormat_v1_0, None)
print(err)
print(data)
print(bytes(data).decode('latin1'))