def remove_duplicates(data_frame):
    """
    Remove duplicate rows from dataframe
    :param data_frame: pandas dataframe
    :return: pandas dataframe without duplicate rows
    """
    num_dups = sum(data_frame.duplicated())
    if num_dups == 0:
        return data_frame
    else:
        df = data_frame.drop_duplicates(keep="first")
        assert sum(df.duplicated()) == 0, "Still duplicates present"
        return df