code: def classes(targetpath):
          
          # Initialise dictionary to store results
          resistance_dict = dict()
          # Find all the .tfa files in the folder
          resistance_files = sorted(glob(os.path.join(targetpath, '*.tfa')))
          # Iterate through each file
          for fasta in resistance_files:
              # Extract the resistance class from the file name and path
              resistance_class = os.path.splitext(os.path.basename(fasta))[0]
              # Initialise the resistance class as a set in the dictionary
              resistance_dict[resistance_class] = set()
              # Open the file
              with open(fasta) as resistance:
                  # Iterate through the FASTA records
                  for record in SeqIO.parse(resistance, 'fasta'):
                      # Replace dashes with underscores
                      record.id = record.id.replace('-', '_')
                      # Add the gene name to the set
                      resistance_dict[resistance_class].add(record.id)
          return resistance_dict
docs: Uses .tfa files included in the ResFinder database to determine the resistance class of gene matches
          :param targetpath: Path to database files
          :return: Dictionary of resistance class: gene set