old_contents: """Converts a number into words using a major system."""
  import argparse
  
  
  class ConverterMajorSystem():
      """class for converting a number to words using the major system."""
  
      def __init__(self, path):
          """Initialize class and copy path to major system."""
          super(ConverterMajorSystem, self).__init__()
          self.major_list = self.__read_major_list(path)
  
      def __read_major_list(self, path):
          """Read the csv-file of a major list and return the parsed list as dict."""
          try:
              major_list = dict()
              with open(path, 'r') as file:
                  for line in file:
                      number, word = line.split(';')
                      major_list[number] = word
              return major_list
          except (IOError, OSError):
              print('Some errors occured while reading the major-list file.')
              print('Check, if the path to the file is correct and if the file is in the correct format.')
  
  
  if __name__ == '__main__':
      parser = argparse.ArgumentParser(description='Converts a number into words using a major system')
      parser.add_argument('major_list', help='file containing a major list in csv-format')
  
      args = parser.parse_args()
      converter = ConverterMajorSystem(args.major_list)
  
new_contents: """Converts a number into words using a major system."""
  import argparse
  
  
  class ConverterMajorSystem():
      """class for converting a number to words using the major system."""
  
      def __init__(self, path):
          """Initialize class and copy path to major system."""
          super(ConverterMajorSystem, self).__init__()
          self.major_list = self.__read_major_list(path)
  
      def __read_major_list(self, path):
          """Read the csv-file of a major list and return the parsed list as dict."""
          major_list = dict()
          with open(path, 'r') as file:
              for line in file:
                  number, word = line.split(';')
                  major_list[number] = word
          return major_list
  
      
  if __name__ == '__main__':
      parser = argparse.ArgumentParser(description='Converts a number into words using a major system')
      parser.add_argument('major_list', help='file containing a major list in csv-format')
  
      args = parser.parse_args()
      converter = ConverterMajorSystem(args.major_list)
  
subject: Remove catching the IOError