Data mining of CVR
>>> from cvrminer.cvrfile import CvrFile
>>> from cvrminer.virksomhed import Virksomhed
>>> filename = '/home/fnielsen/data/cvr/cvr-permanent.json' # or whatever
>>> data = next(CvrFile(filename))
>>> virksomhed = Virksomhed(data)
>>> virksomhed.antal_ansatte
0
>>> cvr_file = CvrFile(filename)
>>> cvr_file.write_virksomhed_features_file() # and wait