TypeError: string indices must be integers while running example script

[J-HowHuang]

Describe the bug
TypeError: string indices must be integers while running example script

To Reproduce
Steps to reproduce the behavior:

1. install from source code poetry add ../fog_x -E rtx
2. run example script

import fog_x

# 🦊 Dataset Creation 
# from distributed dataset storage 
dataset = fog_x.Dataset(
    name="demo_ds",
    path="~/test_dataset", # can be AWS S3, Google Bucket! 
)  

# 🦊 Data collection: 
# create a new trajectory
episode = dataset.new_episode()
# collect step data for the episode
episode.add(feature = "arm_view", value = "image1.jpg")
# Automatically time-aligns and saves the trajectory
episode.close()

# 🦊 Data Loading:
# load from existing RT-X/Open-X datasets
dataset.load_rtx_episodes(
    name="berkeley_autolab_ur5",
    additional_metadata={"collector": "User 2"}
)

# 🦊 Data Management and Analytics: 
# Compute and memory efficient filter, map, aggregate, groupby
episode_info = dataset.get_episode_info()
desired_episodes = episode_info.filter(episode_info["collector"] == "User 2")

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots

python examples/example_fogx_collector.py
I 2024-04-29 22:36:24,783 dataset.py:104] Dataset path: /home/ubuntu/test_dataset
I 2024-04-29 22:36:24,784 polars_connector.py:144] Prepare to load table demo_ds loaded from /home/ubuntu/test_dataset/demo_ds.parquet.
I 2024-04-29 22:36:24,795 polars_connector.py:152] Table demo_ds loaded from /home/ubuntu/test_dataset/demo_ds.parquet.
I 2024-04-29 22:36:24,813 db_manager.py:293] Closing the episode with metadata {}
2024-04-29 22:36:25.753912: I external/local_tsl/tsl/cuda/cudart_stub.cc:32] Could not find cuda drivers on your machine, GPU will not be used.
2024-04-29 22:36:25.758487: I external/local_tsl/tsl/cuda/cudart_stub.cc:32] Could not find cuda drivers on your machine, GPU will not be used.
2024-04-29 22:36:25.826837: I tensorflow/core/platform/cpu_feature_guard.cc:210] This TensorFlow binary is optimized to use available CPU instruct
ions in performance-critical operations.
To enable the following instructions: AVX2 AVX512F FMA, in other operations, rebuild TensorFlow with the appropriate compiler flags.
2024-04-29 22:36:27.131030: W tensorflow/compiler/tf2tensorrt/utils/py_utils.cc:38] TF-TRT Warning: Could not find TensorRT
2024-04-29 22:36:27.799667: W external/local_tsl/tsl/platform/cloud/google_auth_provider.cc:184] All attempts to get a Google authentication beare
r token failed, returning an empty token. Retrieving token from files failed with "NOT_FOUND: Could not locate the credentials file.". Retrieving
token from GCE failed with "FAILED_PRECONDITION: Error executing an HTTP request: libcurl code 6 meaning 'Couldn't resolve host name', error detai
ls: Could not resolve host: metadata.google.internal".
I 2024-04-29 22:36:28,023 dataset_info.py:599] Load dataset info from gs://gresearch/robotics/berkeley_autolab_ur5/0.1.0
I 2024-04-29 22:36:28,575 logging_logger.py:49] Constructing tf.data.Dataset berkeley_autolab_ur5 for split None, from gs://gresearch/robotics/ber
keley_autolab_ur5/0.1.0
I 2024-04-29 22:36:28,576 dataset.py:381] train
Traceback (most recent call last):
  File "/home/ubuntu/FogX-Store/examples/example_fogx_collector.py", line 20, in <module>
    dataset.load_rtx_episodes(
  File "/home/ubuntu/.cache/pypoetry/virtualenvs/fogxstore-nGESZMNh-py3.10/lib/python3.10/site-packages/fog_x/dataset.py", line 385, in load_rtx_e
pisodes
    for step in tf_episode["steps"]:
TypeError: string indices must be integers

Desktop (please complete the following information):

• OS: Ubuntu 22.04 LTS
• Poetry: 1.8.2
• Python: 3.10.12

Additional context
Add any other context about the problem here.

[KeplerC]

commit 1c6e2f8 fix this issue. It's caused by not specifying the split in tfds.

I do see #13 if running the example from the repo. needs more look. but your issue is resolved