code: def entry_verifier(entries, regex, delimiter):
      
  
      cregex = re.compile(regex)  # Compiling saves time if many entries given
  
      # Encode raw delimiter in order to split a bad entry
      python_version = int(sys.version.split('.')[0])
      decoder = 'unicode-escape' if python_version == 3 else 'string-escape'
      dedelimiter = codecs.decode(delimiter, decoder)
  
      for entry in entries:
          match = re.match(cregex, entry)
  
          # Match failed, check regex and entry parts for error
          if not match:
              split_regex = regex.split(delimiter)
              split_entry = entry.split(dedelimiter)
              part = 0  # "Enumerate" zipped iter
              for regex_segment, entry_segment in zip(split_regex, split_entry):
                  # Ensure regex_segment only matches entire entry_segment
                  if not regex_segment[0] == '^':
                      regex_segment = '^' + regex_segment
                  if not regex_segment[-1] == '$':
                      regex_segment += '$'
  
                  # If segment fails, raise error and store info on failure
                  if not re.match(regex_segment, entry_segment):
                      raise FormatError(template=regex_segment,
                                        subject=entry_segment,
                                        part=part)
  
                  part += 1
docs: Checks each entry against regex for validity,
  
      If an entry does not match the regex, the entry and regex
      are broken down by the delimiter and each segment is analyzed
      to produce an accurate error message.
  
      Args:
          entries (list): List of entries to check with regex
  
          regex (str): Regular expression to compare entries with
  
          delimiter (str): Character to split entry and regex by, used to check
              parts of entry and regex to narrow in on the error
  
      Raises:
          FormatError: Class containing regex match error data
  
      Example:
          >>> regex = r'^>.+\\n[ACGTU]+\\n$'
          >>> entry = [r'>entry1\\nAGGGACTA\\n']
          >>> entry_verifier(entry, regex, '\\n')