old_contents: import unicodedata
  
  class Normalizer:
  
      def normalize(text):
          """
          Normalize a given text applying all normalizations.
  
          Params:
              text: The text to be processed.
  
          Returns:
              The text normalized.
          """
          text = Normalizer.remove_extra_whitespaces(text)
          text = Normalizer.replace_hyphens(text)
          text = Normalizer.remove_accent_marks(text)
  
          return text.lower()
  
      @staticmethod
      def replace_hyphens(text):
          """
          Remove hyphens from input text.
  
          Params:
              text: The text to be processed.
  
          Returns:
              The text without hyphens.
          """
          return text.replace('-', ' ')
  
      @staticmethod
      def remove_extra_whitespaces(text):
          """
          Remove extra whitespaces from input text.
  
          This function removes whitespaces from the beginning and the end of
          the string, but also duplicated whitespaces between words.
  
          Params:
              text: The text to be processed.
  
          Returns:
              The text without extra whitespaces.
          """
          return ' '.join(text.strip().split());
  
      @staticmethod
      def remove_accent_marks(text):
          """
          Remove accent marks from input text.
  
          Params:
              text: The text to be processed.
  
          Returns:
              The text without accent marks.
          """
          return ''.join(c for c in unicodedata.normalize('NFKD', text.replace('ñ', '/n/'))
                         if unicodedata.category(c) != 'Mn').replace('/n/', 'ñ')
  
new_contents: import unicodedata
  from unidecode import unidecode
  class Normalizer:
  
      def normalize(text):
          """
          Normalize a given text applying all normalizations.
  
          Params:
              text: The text to be processed.
  
          Returns:
              The text normalized.
          """
          text = Normalizer.remove_extra_whitespaces(text)
          text = Normalizer.replace_hyphens(text)
          text = Normalizer.remove_accent_marks(text)
          text = Normalizer.remove_symbols(text)
  
          return text.lower()
  
      @staticmethod
      def replace_hyphens(text):
          """
          Remove hyphens from input text.
  
          Params:
              text: The text to be processed.
  
          Returns:
              The text without hyphens.
          """
          return text.replace('-', ' ')
  
      @staticmethod
      def remove_extra_whitespaces(text):
          """
          Remove extra whitespaces from input text.
  
          This function removes whitespaces from the beginning and the end of
          the string, but also duplicated whitespaces between words.
  
          Params:
              text: The text to be processed.
  
          Returns:
              The text without extra whitespaces.
          """
          return ' '.join(text.strip().split());
  
      @staticmethod
      def remove_accent_marks(text):
          """
          Remove accent marks from input text.
  
          Params:
              text: The text to be processed.
  
          Returns:
              The text without accent marks.
          """
          return ''.join(c for c in unicodedata.normalize('NFKD', text.replace('ñ', '/n/'))
                         if unicodedata.category(c) != 'Mn').replace('/n/', 'ñ').strip()
  
      @staticmethod
      def remove_symbols(text):
          """
          Remove symbols from input text.
  
          Params:
              text: The text to be processed.
  
          Returns:
              The text without symbols.
          """
          return ''.join(c for c in unicodedata.normalize('NFKD', text.replace('ñ', '/n/'))
                         if unicodedata.category(c) not in ['Sc', 'Sk', 'Sm', 'So']).replace('/n/', 'ñ').strip()
  
subject: Add function to clean symbols