def null_count(df):
    return df.isnull().sum().sum()

# Split addresses into three columns (df['city'], df['state'], and df['zip'])
# def addy_split(add_series):
#     df[len_str] = df['owner city state zip'].str.split(',').apply(len)
#     df['num_commas'] = df['Owner City State Zip'].str.count(',')
#     return df


# Return a new column with the full name from
# a State abbreviation column -> An input of FL would return Florida


def add_state_names_column(my_df):
    '''
    add a column of corrsponding state names to a dataframe'

    Pramas (my_df) a DataFrame with a column called "abbrev" that has state abbrevations

    Return a copy of the original dataframe,but with an extra column.
    '''
    new_df = my_df.copy()

    states = {"CA": "California", "CO": "Cplorado", "CT": "Conn"}

    new_df["st_name"] = new_df["abbrev"].map(states)

    breakpoint()

    return my_df


if __name__ == "__main__":

    df = DataFrame({"abrev": ["CA", "CO", "CT", "DC", "TX"]})
    print(df.head())

    add_state_names_column(my_df)
    print(df.head())
