Hello! I have this weird error when trying to catalog a dictionary as a json file:

Object of type type is not JSON serializable

I wonder what I did wrong, because I followed this tutorial closely: https://demo.kedro.org/ My catalog entry:

tune.base_batchnorm_l2reg.params:
  type: tracking.JSONDataset
  filepath: data/07_tuning_results/base_batchnorm_l2reg/params.json
  versioned: True

Do you have an idea of why this is happening?

so this is just an error passed up from

json.dumps

It is a simple dictionary (non-nested): { 'model_class': 'NNFreq_no_batchnorm', 'optimizer': class 'torch.optim.adam.Adam', 'early_stopping_patience': 10, 'lr_scheduler_factor': 0.2, 'lr_scheduler_patience': 5, 'batch_size': [64], 'optimizer__lr': [0.0001], 'module__act': [class 'torch.nn.modules.activation.ReLU', class 'torch.nn.modules.activation.Tanh']}

Oh, need to transform back to string.

yes exactly

Thanks, I'm pretty new to Python, that's why XD

no worries! the general rule of json is that you need to work with primitives like string, int, list etc. But when you get to complex objects, particularly those that wont work outside of Python you’ll need to either default to string or be creative in other ways.

Oh yes, makes sense, only Python can understand these kinds of objects.