def format_coords(df, col_to_convert, col_new_name):
    """
    Takes col_to_convert and creates a list of a set of strings that
    contain coordinates in an integer form.

    Parameters
    ----------
    df : df
        pd.DataFrame that contains Neotoma information.
    col_to_convert :  string
        Name of column of df. This column has latitude and longitude
        coordinates
    col_new_name : string
        Name of new column of df.

    Returns
    -------
    df: pd.DataFrame
        pd.DataFrame with new column `col_new_name` which contains a list of
        unique positive integer coordinates.
    """
    df[col_new_name] = df[col_to_convert]\
        .apply(lambda x: [int(abs(i)) for i in x])\
        .apply(lambda x: [str(i) for i in x])\
        .replace('-', '', regex=True)\
        .apply(lambda x: list(set(x)))

    return df