code: def _get_parts_of_format_string(resolved_string, literal_texts, format_specs):
      
      _text = resolved_string
      bits = []
  
      if literal_texts[-1] != '' and _text.endswith(literal_texts[-1]):
          _text = _text[:-len(literal_texts[-1])]
          literal_texts = literal_texts[:-1]
          format_specs = format_specs[:-1]
  
      for i, literal_text in enumerate(literal_texts):
          if literal_text != '':
              if literal_text not in _text:
                  raise ValueError(("Resolved string must match pattern. "
                                    "'{}' not found.".format(literal_text)))
              bit, _text = _text.split(literal_text, 1)
              if bit:
                  bits.append(bit)
          elif i == 0:
              continue
          else:
              try:
                  format_spec = _validate_format_spec(format_specs[i-1])
                  bits.append(_text[0:format_spec])
                  _text = _text[format_spec:]
              except:
                  if i == len(format_specs) - 1:
                      format_spec = _validate_format_spec(format_specs[i])
                      bits.append(_text[:-format_spec])
                      bits.append(_text[-format_spec:])
                      _text = []
                  else:
                      _validate_format_spec(format_specs[i-1])
      if _text:
          bits.append(_text)
      if len(bits) > len([fs for fs in format_specs if fs is not None]):
          bits = bits[1:]
      return bits
docs: Inner function of reverse_format, returns the resolved value for each
      field in pattern.