def parse_yes_no_str(bool_str):
    """Parse a string serialization of boolean data as yes (Y) or no (N).

    Prase a string serialization of boolean data where True is "Y" and False is
    "N" case-insensitive.

    @param bool_str: The string to parse.
    @type bool_str: str
    @return: The interpreted string.
    @rtype: bool
    @raise ValueError: Raised if the passed string is not equal to 'N' or 'Y'
        case insensitive.
    """
    lower_bool_str = bool_str.lower()
    if lower_bool_str == 'n':
        return False
    elif lower_bool_str == 'y':
        return True
    else:
        raise ValueError('%s not a valid boolean string.' % bool_str)
