def check_date_bounds(df, date_low, date_high):
    if (not ((date_low <= df['date']) & (df['date'] < date_high)).all()):
        raise ValueError('Date out of bounds')
    return True
def check_date_bounds(df, date_low, date_high):
    if (not ((date_low <= df['date']) & (df['date'] < date_high)).all()):
        raise ValueError('Date out of bounds')
    return True