Can't cast Trainer automatically generated args to their required types

❓ Questions and Help

What is your question?

I’m not sure, that this is a bug, so I put it like a question. The problem is: if I want to add the Trainer arguments to my custom ArgumentParser object, I call the add_argparse_args Trainer classmethod. But this method doesn’t cast the Trainer arguments to their required types. It forces me to cast the arguments by myself. Like so:

trainer_args.update(
        {
            'accumulate_grad_batches': int(trainer_args['accumulate_grad_batches']),
            'train_percent_check': float(trainer_args['train_percent_check']),
            'val_percent_check': float(trainer_args['val_percent_check']),
            'val_check_interval': int(trainer_args['val_check_interval']),
            'track_grad_norm': int(trainer_args['track_grad_norm']),
            'max_epochs': int(trainer_args['max_epochs']),
            'precision': int(trainer_args['precision']),
            'gradient_clip_val': float(trainer_args['gradient_clip_val']),
        }
)

And after that, I can pass updated arguments to the Trainer:

trainer = pytorch_lightning.Trainer(
        **trainer_args
)

And I can’t find a central place, where the Trainer handles an automatically generated arguments (their types).

What have you tried?

I’ve tried to pass arguments to the trainer without handling their types. For instance, if i’ll not cast accumulate_grad_batches to the integer type, the exception will be raised:

TypeError: Gradient accumulation supports only int and dict types

What’s your environment?

• OS: [Linux]
• Packaging [pip]
• Version [0.7.1]

[alexeykarnachev]

@williamFalcon this issue is about assigning types for the automatically added arguments. By default argparser assumes that they are strings. And these string typed args will be passed to the trainer constructor, and will break it. So, this issue is about types casting, but not about any new functionality

[williamFalcon]

https://pytorch-lightning.readthedocs.io/en/0.7.1/hyperparameters.html#trainer-args