Function to recode ECOSUBCD to DIVCD

divcd.py

def recode_divcd(df: pd.DataFrame) -> pd.DataFrame:
    """
    Convert the ECOSUBCD column to DIVCD

    Parameters
    ----------
    df : pd.DataFrame
        The input DataFrame

    Returns
    -------
    pd.DataFrame
        The input DataFrame with the ECOSUBCD column converted to DIVCD
    """
    # Extract the numeric part and convert to integer
    df["DIVCD"] = df["ECOSUBCD"].str.extract("(\d+)").astype(int)
    # Round down to the nearest 10
    df["DIVCD"] = (df["DIVCD"] // 10) * 10
    # Add 'M' prefix if originally present
    df["DIVCD"] = df.apply(
        lambda row: "M" + str(row["DIVCD"])
        if row["ECOSUBCD"].startswith("M")
        else row["DIVCD"],
        axis=1,
    )
    return df