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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 _vertex_list_to_dataframe(ls, id_column_name):
 """ Convert a list of vertices into dataframe. """

    assert HAS_PANDAS, 'Cannot use dataframe because Pandas is not available or version is too low.'
    cols = reduce(set.union, (set(v.attr.keys()) for v in ls))
    df = pd.DataFrame({id_column_name: [v.vid for v in ls]})
    for c in cols:
        df[c] = [v.attr.get(c) for v in ls]
    return df