code: # 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,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  import random
  import argparse
  import numpy as np
  import paddle
  
  from paddleseg.utils import logger, get_sys_env
  
  import utils
  from cvlibs import Config
  from script.train import Trainer
  from datasets import CityDataset, GTA5Dataset, SYNTHIADataset
  
  
  def parse_args():
      parser = argparse.ArgumentParser(description='Model training')
  
      # params of training
      parser.add_argument(
          "--config", dest="cfg", help="The config file.", default=None, type=str)
      parser.add_argument(
          '--iters',
          dest='iters',
          help='iters for training',
          type=int,
          default=None)
      parser.add_argument(
          '--batch_size',
          dest='batch_size',
          help='Mini batch size of one gpu or cpu',
          type=int,
          default=None)
      parser.add_argument(
          '--learning_rate',
          dest='learning_rate',
          help='Learning rate',
          type=float,
          default=None)
      parser.add_argument(
          '--save_interval',
          dest='save_interval',
          help='How many iters to save a model snapshot once during training.',
          type=int,
          default=1000)
      parser.add_argument(
          '--resume_model',
          dest='resume_model',
          help='The path of resume model',
          type=str,
          default=None)
      parser.add_argument(
          '--save_dir',
          dest='save_dir',
          help='The directory for saving the model snapshot',
          type=str,
          default='./output')
      parser.add_argument(
          '--keep_checkpoint_max',
          dest='keep_checkpoint_max',
          help='Maximum number of checkpoints to save',
          type=int,
          default=5)
      parser.add_argument(
          '--num_workers',
          dest='num_workers',
          help='Num workers for data loader',
          type=int,
          default=0)
      parser.add_argument(
          '--do_eval',
          dest='do_eval',
          help='Eval while training',
          action='store_true')
      parser.add_argument(
          '--log_iters',
          dest='log_iters',
          help='Display logging information at every log_iters',
          default=10,
          type=int)
      parser.add_argument(
          '--use_vdl',
          dest='use_vdl',
          help='Whether to record the data to VisualDL during training',
          action='store_true')
      parser.add_argument(
          '--seed',
          dest='seed',
          help='Set the random seed during training.',
          default=42,
          type=int)
      parser.add_argument(
          '--fp16', dest='fp16', help='Whther to use amp', action='store_true')
      parser.add_argument(
          '--data_format',
          dest='data_format',
          help=
          'Data format that specifies the layout of input. It can be "NCHW" or "NHWC". Default: "NCHW".',
          type=str,
          default='NCHW')
  
      return parser.parse_args()
  
  
  def main(args):
      if args.seed is not None:
          paddle.seed(args.seed)
          np.random.seed(args.seed)
          random.seed(args.seed)
          logger.info('Set seed to {}'.format(args.seed))
  
      env_info = get_sys_env()
      info = ['{}: {}'.format(k, v) for k, v in env_info.items()]
      info = '\n'.join(['', format('Environment Information', '-^48s')] + info +
                       ['-' * 48])
      logger.info(info)
  
      place = 'gpu' if env_info['Paddle compiled with cuda'] and env_info[
          'GPUs used'] else 'cpu'
  
      paddle.set_device(place)
  
      if not args.cfg:
          raise RuntimeError('No configuration file specified.')
  
      cfg = Config(
          args.cfg,
          learning_rate=args.learning_rate,
          iters=args.iters,
          batch_size=args.batch_size)
  
      if cfg.dic["data"]["source"]["dataset"] == 'synthia':
          train_dataset_src = SYNTHIADataset(
              split='train', **cfg.dic["data"]["source"]["kwargs"])
          val_dataset_src = SYNTHIADataset(
              split='val', **cfg.dic["data"]["source"]["kwargs"])
      elif cfg.dic["data"]["source"]["dataset"] == 'gta5':
          train_dataset_src = GTA5Dataset(
              split='train', **cfg.dic["data"]["source"]["kwargs"])
          val_dataset_src = GTA5Dataset(
              split='val', **cfg.dic["data"]["source"]["kwargs"])
      else:
          raise NotImplementedError()
      if cfg.dic["data"]["target"]["dataset"] == 'cityscapes':
          train_dataset_tgt = CityDataset(
              split='train', **cfg.dic["data"]["target"]["kwargs"])
          val_dataset_tgt = CityDataset(
              split='val', **cfg.dic["data"]["target"]["kwargs"])
      else:
          raise NotImplementedError()
  
      val_dataset_tgt = val_dataset_tgt if args.do_eval else None
      val_dataset_src = val_dataset_src if args.do_eval else None
  
      if train_dataset_src is None:
          raise RuntimeError(
              'The training dataset is not specified in the configuration file.')
      elif len(train_dataset_src) == 0:
          raise ValueError(
              'The length of train_dataset is 0. Please check if your dataset is valid'
          )
  
      msg = '\n---------------Config Information---------------\n'
      msg += str(cfg)
      msg += '------------------------------------------------'
      logger.info(msg)
  
      trainer = Trainer(model=cfg.model, cfg=cfg.dic)
      trainer.train(
          train_dataset_src,
          train_dataset_tgt,
          val_dataset_tgt=val_dataset_tgt,
          val_dataset_src=val_dataset_src,
          optimizer=cfg.optimizer,
          save_dir=args.save_dir,
          iters=cfg.iters,
          batch_size=cfg.batch_size,
          resume_model=args.resume_model,
          save_interval=args.save_interval,
          log_iters=args.log_iters,
          num_workers=args.num_workers,
          use_vdl=args.use_vdl,
          keep_checkpoint_max=args.keep_checkpoint_max,
          test_config=cfg.test_config)
  
  
  if __name__ == '__main__':
      args = parse_args()
      main(args)
  
apis: numpy.random.seed