Saving and loading a model in Pytorch?

What is wrong with doing:

def save_ckpt(path_to_ckpt):
    from pathlib import Path
    import dill as pickle
    ## Make dir. Throw no exceptions if it already exists
    path_to_ckpt.mkdir(parents=True, exist_ok=True)
    ckpt_path_plus_path = path_to_ckpt / Path('db')

    ## Pickle args
    db['crazy_mdl'] = crazy_mdl
    with open(ckpt_path_plus_path , 'ab') as db_file:
        pickle.dump(db, db_file)