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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def handle_uploaded_files(uploaded_files):
 """Handles downstream processes using metadata about the uploaded files from React side."""

    if uploaded_files:
        uploaded_files = json.loads(uploaded_files)[0]
        _id = uploaded_files.get('id')
        # Strip extension from filename
        _filename = os.path.splitext(uploaded_files.get('filename'))[0]

        # Create a dataset
        dataset = g.client.Dataset.get_or_create_by_full_path('~/' + _filename)

        # Import the file into the dataset
        g.client.DatasetImport.create(
            dataset_id=dataset.id,
            object_id=_id
        )

        # Wait until activity is completed
        dataset.activity(follow=True)

        SELECTED_COLS = ['col_a', 'col_b', 'col_c']
        query = dataset.query(fields=SELECTED_COLS)

        return html.Div(
            dt.DataTable(
                id='data-table',
                rows=list(query),
                columns=SELECTED_COLS
            )
        )