def _col_containing_digit_or_digits(record, header_len, alphanumeric_cols):
    """Returns index of column in record with both non-digits and digits if
    one exists. Otherwise, returns None."""
    if record.shape[1] == header_len:
        for col in alphanumeric_cols:
            for char in record[col]:
                if char.isdigit():
                    return col
    return None
