app.py

import gradio as gr
import requests
from huggingface_hub import HfApi

session = requests.Session()

css = """
@media (prefers-color-scheme: dark) {
    .transparent-dropdown, .transparent-dropdown .container .wrap  {
        background: var(--bg-dark);
    }
}
@media (prefers-color-scheme: light) {
    .transparent-dropdown, .transparent-dropdown .container .wrap  {
        background: var(--bg);
    }
}
"""

with gr.Blocks(css=css) as demo:
    with gr.Row():
        with gr.Column(scale=4):
            with gr.Group():
                dataset_dropdown = gr.Dropdown(label="Dataset", allow_custom_value=True, interactive=True)
                with gr.Row():
                    subset_dropdown = gr.Dropdown(info="Subset", show_label=False, visible=False, elem_classes="transparent-dropdown")
                    split_dropdown = gr.Dropdown(info="Split", show_label=False, visible=False, elem_classes="transparent-dropdown")
        gr.LoginButton()
    loading_codes_json = gr.JSON(visible=False)
    dataset_subset_split_textbox = gr.Textbox(visible=False)
    dataframe = gr.DataFrame()

    @demo.load(outputs=dataset_dropdown)
    def fetch_datasets(request: gr.Request, oauth_token: gr.OAuthToken | None):
        api = HfApi(token=oauth_token.token if oauth_token else None)
        datasets = list(api.list_datasets(limit=3, sort="trendingScore", direction=-1, filter=["format:parquet"]))
        if oauth_token and (user := api.whoami().get("user")):
            datasets += list(api.list_datasets(limit=3, sort="trendingScore", direction=-1, filter=["format:parquet"], author=user))
        dataset = request.query_params.get("dataset") or datasets[0].id
        return {dataset_dropdown: gr.Dropdown(choices=[dataset.id for dataset in datasets], value=dataset)}

    @dataset_dropdown.change(inputs=dataset_dropdown, outputs=loading_codes_json)
    def fetch_read_parquet_loading(dataset: str):
        if "/" not in dataset.strip().strip("/"):
            return []
        resp = session.get(f"https://datasets-server.huggingface.co/compatible-libraries?dataset={dataset}", timeout=3).json()
        return ([lib["loading_codes"] for lib in resp.get("libraries", []) if lib["function"] == "dd.read_parquet"] or [[]])[0] or []

    @loading_codes_json.change(inputs=loading_codes_json, outputs=[subset_dropdown, split_dropdown])
    def show_subset_dropdown(loading_codes: list[dict]):
        subsets = [loading_code["config_name"] for loading_code in loading_codes]
        subset = (subsets or [""])[0]
        splits = ([list(loading_code["arguments"]["splits"]) for loading_code in loading_codes if loading_code["config_name"] == subset] or [[]])[0]
        split = (splits or [""])[0]
        return gr.Dropdown(subsets, value=subset, visible=len(subsets) > 1), gr.Dropdown(splits, value=split, visible=len(splits) > 1)

    @subset_dropdown.change(inputs=[loading_codes_json, subset_dropdown], outputs=split_dropdown)
    def show_split_dropdown(loading_codes: list[dict], subset: str):
        splits = ([list(loading_code["arguments"]["splits"]) for loading_code in loading_codes if loading_code["config_name"] == subset] or [[]])[0]
        split = (splits or [""])[0]
        return gr.Dropdown(splits, value=split, visible=len(splits) > 1)
        


if __name__ == "__main__":
    demo.launch()