def safe_unicode(str_, from_encoding=None):

    """

    safe unicode function. Does few trick to turn str_ into unicode

    In case of UnicodeDecode error we try to return it with encoding detected

    by chardet library if it fails fallback to unicode with errors replaced

    :param str_: string to decode

    :rtype: unicode

    :returns: unicode object

    """

    if isinstance(str_, unicode):

        return str_

    if not from_encoding:

        import kallithea

        DEFAULT_ENCODINGS = aslist(kallithea.CONFIG.get('default_encoding',

                                                        'utf-8'), sep=',')

        from_encoding = DEFAULT_ENCODINGS

    if not isinstance(from_encoding, (list, tuple)):

        from_encoding = [from_encoding]

    try:

        return unicode(str_)

    except UnicodeDecodeError:

        pass

    for enc in from_encoding:

        try:

            return unicode(str_, enc)

        except UnicodeDecodeError:

            pass

    try:

        import chardet

        encoding = chardet.detect(str_)['encoding']

        if encoding is None:

            raise Exception()

        return str_.decode(encoding)

    except (ImportError, UnicodeDecodeError, Exception):

        return unicode(str_, from_encoding[0], 'replace')

def safe_str(unicode_, to_encoding=None):

    """

    safe str function. Does few trick to turn unicode_ into string

    In case of UnicodeEncodeError we try to return it with encoding detected

    by chardet library if it fails fallback to string with errors replaced

    :param unicode_: unicode to encode

    :rtype: str

    :returns: str object

    """

    # if it's not basestr cast to str

    if not isinstance(unicode_, basestring):

        return str(unicode_)

    if isinstance(unicode_, str):

        return unicode_

    if not to_encoding:

        import kallithea

        DEFAULT_ENCODINGS = aslist(kallithea.CONFIG.get('default_encoding',

                                                        'utf-8'), sep=',')

        to_encoding = DEFAULT_ENCODINGS

    if not isinstance(to_encoding, (list, tuple)):

        to_encoding = [to_encoding]

    for enc in to_encoding:

        try:

            return unicode_.encode(enc)

        except UnicodeEncodeError:

            pass

    try:

        import chardet

        encoding = chardet.detect(unicode_)['encoding']

        if encoding is None:

            raise UnicodeEncodeError()

        return unicode_.encode(encoding)

    except (ImportError, UnicodeEncodeError):

        return unicode_.encode(to_encoding[0], 'replace')