import re


def find_col(df, regex_str):
    """Return column names that satify regex d condition

    Parameters
    ----------
    df : pd.DataFrame
        DataFrame to folter columns
    regex_str : str
        regex condition

    Returns
    -------
    list
        list of column names that satisfy condition
    """
    r = re.compile(regex_str)
    mylist = df.columns.to_list()
    return list(filter(r.findall, mylist))