NumberParseException not handled

File "/usr/src/BiscuIT-ng/apps/official/BiscuIT-App-SchILD-NRW/biscuit/apps/schild_nrw/util.py", line 88, in <lambda>
    csv_converters = {'phone_number': lambda v: phonenumbers.parse(v, 'DE') if v else '',
  File "/srv/biscuit/lib/python3.7/site-packages/phonenumbers/phonenumberutil.py", line 2808, in parse
    "The string supplied did not seem to be a phone number.")
phonenumbers.phonenumberutil.NumberParseException: (1) The string supplied did not seem to be a phone number.