class_docstr: Convert between text-label and text-index 
class_docstr_tok: ["Convert","between","text-label","and","text-index"]
code: def __call__(self, preds, label=None, *args, **kwargs):
      if self.key is not None:
          preds = preds[self.key]
  
      label_list = self.label_list
      if label_list is None:
          label_list = {idx: idx for idx in range(preds.shape[-1])}
  
      if isinstance(preds, paddle.Tensor):
          preds = preds.numpy()
  
      pred_idxs = preds.argmax(axis=1)
      decode_out = [
          (label_list[idx], preds[i, idx])
          for i, idx in enumerate(pred_idxs)
      ]
      if label is None:
          return decode_out
      label = [(label_list[idx], 1.0) for idx in label]
      return decode_out, label
  
imports: import paddle
label_desc: Use image node_id 2 for calling the ClsPostProcess obj's underlying member method code with example usage: obj.__call__(preds, label) and returns: decode_out,  label, decode_out