Source code for paddlenlp.taskflow.text_generation

# coding:utf-8
# Copyright (c) 2021  PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
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import paddle

from ..data import Pad, Stack, Tuple
from ..transformers import GPTChineseTokenizer, GPTForGreedyGeneration, GPTTokenizer
from .task import Task
from .utils import download_file, static_mode_guard

usage = r"""
         """

URLS = {
    "gpt-cpm-large-cn": [
        "https://bj.bcebos.com/paddlenlp/taskflow/text_generation/gpt-cpm/gpt-cpm-large-cn_params.tar",
        "5aad6f81053cfdbba4797f044fcf66d1",
    ],
}


[docs]class TextGenerationTask(Task): """ The text generation model to predict the question or chinese poetry. Args: task(string): The name of task. model(string): The model name in the task. kwargs (dict, optional): Additional keyword arguments passed along to the specific task. """ def __init__(self, task, model, **kwargs): super().__init__(task=task, model=model, **kwargs) # Default to static mode self._static_mode = True self._usage = usage if self._static_mode: download_file(self._task_path, "gpt-cpm-large-cn_params.tar", URLS[self.model][0], URLS[self.model][1]) self._get_inference_model() else: self._construct_model(model) self._construct_tokenizer(model) self.kwargs["generation_task"] = task def _construct_input_spec(self): """ Construct the input spec for the convert dygraph model to static model. """ self._input_spec = [paddle.static.InputSpec(shape=[None, None], dtype="int64", name="token_ids")] def _construct_model(self, model): """ Construct the inference model for the predictor. """ model_instance = GPTForGreedyGeneration.from_pretrained(self.model, max_predict_len=32) # Load the model parameter for the predict model_instance.eval() self._model = model_instance def _construct_tokenizer(self, model): """ Construct the tokenizer for the predictor. """ if self.model == "gpt-cpm-large-cn": tokenizer_instance = GPTChineseTokenizer.from_pretrained(model) else: tokenizer_instance = GPTTokenizer.from_pretrained(model) self._tokenizer = tokenizer_instance def _preprocess(self, inputs, padding=True, add_special_tokens=True): """ Transform the raw text to the model inputs, two steps involved: 1) Transform the raw text to token ids. 2) Generate the other model inputs from the raw text and token ids. """ inputs = self._check_input_text(inputs) # Get the config from the kwargs batch_size = self.kwargs["batch_size"] if "batch_size" in self.kwargs else 1 generation_task = self.kwargs["generation_task"] if "generation_task" in self.kwargs else "question_answering" def select_few_shot_input(model_name, generation_task): pre_input = "" if generation_task not in ["question_answering", "poetry_generation"]: raise ValueError("The generation task must be question or poetry") if model_name == "gpt-cpm-large-cn": if generation_task == "question_answering": pre_input = "问题:中国的首都是哪里?答案:北京。\n问题:{} 答案:" else: pre_input = "默写古诗: 大漠孤烟直,长河落日圆。\n{}" return pre_input pre_input = select_few_shot_input(self.model, generation_task) examples = [] filter_inputs = [] for input_text in inputs: if not (isinstance(input_text, str) and len(input_text) > 0): continue filter_inputs.append(input_text) few_shot_input = pre_input.format(input_text) ids = self._tokenizer(few_shot_input)["input_ids"] examples.append((ids, len(ids))) batchify_fn = lambda samples, fn=Tuple( Pad(axis=0, pad_val=0, dtype="int64"), Stack(dtype="int64"), # seq_len ): fn(samples) batches = [examples[idx : idx + batch_size] for idx in range(0, len(examples), batch_size)] outputs = {} outputs["text"] = filter_inputs outputs["data_loader"] = batches self._batchify_fn = batchify_fn return outputs def _run_model(self, inputs): """ Run the task model from the outputs of the `_tokenize` function. """ results = [] lens = [] with static_mode_guard(): for batch in inputs["data_loader"]: ids, seq_len = self._batchify_fn(batch) self.input_handles[0].copy_from_cpu(ids) self.predictor.run() result = self.output_handle[0].copy_to_cpu().tolist() results.extend(result) lens.extend(seq_len.tolist()) inputs["results"] = results inputs["lens"] = lens return inputs def _postprocess(self, inputs): """ The model output is tag ids, this function will convert the model output to raw text. """ batch_out = [] preds = inputs["results"] for index in range(0, len(preds)): seq_len = inputs["lens"][index] single_result = {} single_result["text"] = inputs["text"][index] single_result["answer"] = self._tokenizer.convert_ids_to_string(preds[index][seq_len:-1]) batch_out.append(single_result) return batch_out