def remove_blank_columns(doa, columns, sizes):
    """
    Remove columns that are blank.
    - doa: (Dict String (Array String)), dictionary with string keys to arrays of string
    - columns: (Array String), order of keys to write table out as
    RETURN: (Tuple (Array String), (Array Integer)), tuple of new columns with
    blanks removed and new sizes
    """
    new_columns = []
    new_sizes = []
    for col, size in zip(columns, sizes):
        non_blanks = 0
        for row in doa[col]:
            if row is not None and row != "":
                non_blanks += 1
        if non_blanks > 0:
            new_columns.append(col)
            new_sizes.append(size)
    return new_columns, new_sizes