Trainer.add_argparse_args bool type

[fschlatt]

🐛 Bug

The boolean arguments added using Trainer.add_argparse_args always evaluate to True. This is caused by the following lines of the add_argparse_args fucntion:

if isinstance(allowed_type, bool):
    def allowed_type(x):
         return bool(distutils.util.strtobool(x))

Because allowed_type is the actual data type and not an instance of bool. isinstance(bool, bool) is equal to False. bool is bool is equal True

[fschlatt]

I just found the Trainer.add_argparse_args clashes with the auto_lr_find argument as auto_lr_find can be either bool or str. I would propose removing the option to provide a string to auto_lr_find. If I understand correctly then the str option is only there to specify a separate learning rate using argparse anyway. On top of being confusing you could just use hparams.lr and set auto_lr_find to False which is more straightforward