old_contents: # businessid.py - functions for handling Austrian company register numbers
  #
  # Copyright (C) 2015 Holvi Payment Services Oy
  # Copyright (C) 2012, 2013 Arthur de Jong
  #
  # This library is free software; you can redistribute it and/or
  # modify it under the terms of the GNU Lesser General Public
  # License as published by the Free Software Foundation; either
  # version 2.1 of the License, or (at your option) any later version.
  #
  # This library is distributed in the hope that it will be useful,
  # but WITHOUT ANY WARRANTY; without even the implied warranty of
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  # Lesser General Public License for more details.
  #
  # You should have received a copy of the GNU Lesser General Public
  # License along with this library; if not, write to the Free Software
  # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  # 02110-1301 USA
  
  """Austrian Company Register Numbers
  
  The Austrian company register number consist of digits followed by
  a single letter, e.g. "122119m". Sometimes it is presented with preceding
  "FN", e.g. "FN 122119m".
  
  >>> validate('FN 122119m')
  '122119m'
  >>> validate('122119m')
  '122119m'
  >>> validate('m123123')
  Traceback (most recent call last):
      ...
  InvalidFormat: ...
  >>> validate('abc')
  Traceback (most recent call last):
      ...
  InvalidFormat: ...
  """
  
  from stdnum import luhn
  from stdnum.exceptions import *
  from stdnum.util import clean
  
  
  def compact(number):
      """Convert the number to the minimal representation. This strips the
      number of any valid separators and removes surrounding whitespace.
      Preceding "FN" is also removed."""
      number = clean(number, ' -./').strip()
      if number.startswith('FN'):
          number = number[2:]
      return number
  
  
  def validate(number):
      """Checks to see if the number provided is a valid company register number.
      This checks only the formatting."""
      number = compact(number)
      if not number[-1:].isalpha() or not number[:-1].isdigit():
          raise InvalidFormat()
      return number
  
  
  def is_valid(number):
      """Checks to see if the number provided is a valid company register number.
      This checks only the formatting."""
      try:
          return bool(validate(number))
      except ValidationError:
          return False
  
new_contents: # businessid.py - functions for handling Austrian company register numbers
  #
  # Copyright (C) 2015 Holvi Payment Services Oy
  # Copyright (C) 2012, 2013 Arthur de Jong
  #
  # This library is free software; you can redistribute it and/or
  # modify it under the terms of the GNU Lesser General Public
  # License as published by the Free Software Foundation; either
  # version 2.1 of the License, or (at your option) any later version.
  #
  # This library is distributed in the hope that it will be useful,
  # but WITHOUT ANY WARRANTY; without even the implied warranty of
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  # Lesser General Public License for more details.
  #
  # You should have received a copy of the GNU Lesser General Public
  # License along with this library; if not, write to the Free Software
  # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  # 02110-1301 USA
  
  """Austrian Company Register Numbers
  
  The Austrian company register number consist of digits followed by
  a single letter, e.g. "122119m". Sometimes it is presented with preceding
  "FN", e.g. "FN 122119m".
  
  >>> validate('FN 122119m')
  '122119m'
  >>> validate('122119m')
  '122119m'
  >>> validate('m123123')
  Traceback (most recent call last):
      ...
  InvalidFormat: ...
  >>> validate('abc')
  Traceback (most recent call last):
      ...
  InvalidFormat: ...
  """
  
  from stdnum import luhn
  from stdnum.exceptions import *
  from stdnum.util import clean
  
  
  def compact(number):
      """Convert the number to the minimal representation. This strips the
      number of any valid separators and removes surrounding whitespace.
      Preceding "FN" is also removed."""
      number = clean(number, ' -./').strip()
      if number.upper().startswith('FN'):
          number = number[2:]
      return number
  
  
  def validate(number):
      """Checks to see if the number provided is a valid company register number.
      This checks only the formatting."""
      number = compact(number)
      if not number[-1:].isalpha() or not number[:-1].isdigit():
          raise InvalidFormat()
      return number
  
  
  def is_valid(number):
      """Checks to see if the number provided is a valid company register number.
      This checks only the formatting."""
      try:
          return bool(validate(number))
      except ValidationError:
          return False
  
subject: Check FN as case insensitive