def splitFrom(df, attr, val):
    """
    Split DataFrame in two subset based on year attribute
    :param df: DataFrame to split
    :param attr: attribute on which split data
    :param val: value of attribute where do split
    :return: two subset
    """
    if attr not in df.columns:
        raise ValueError("******* "+attr+" not in DataFrame *******")
    subfd1 = df.loc[df[attr] < val]
    subfd2 = df.loc[df[attr] >= val]
    return subfd1, subfd2