How to use the idna.encode function in idna

def _get_idna_encoded_host(host):
        try:
            from .packages import idna
        except ImportError:
            # tolerate the possibility of downstream repackagers unvendoring `requests`
            # For more information, read: packages/__init__.py
            import idna
            sys.modules['requests.packages.idna'] = idna

        try:
            host = idna.encode(host, uts46=True).decode('utf-8')
        except idna.IDNAError:
            raise UnicodeError
        return host

def idna_encode(name):
        """
        Borrowed wholesale from the Python Cryptography Project. It turns out
        that we can't just safely call `idna.encode`: it can explode for
        wildcard names. This avoids that problem.
        """
        for prefix in [u'*.', u'.']:
            if name.startswith(prefix):
                name = name[len(prefix):]
                return prefix.encode('ascii') + idna.encode(name)
        return idna.encode(name)

def _get_idna_encoded_host(host):
        import idna

        try:
            host = idna.encode(host, uts46=True).decode('utf-8')
        except idna.IDNAError:
            raise UnicodeError
        return host

def idna_encode(name):
        """
        Borrowed wholesale from the Python Cryptography Project. It turns out
        that we can't just safely call `idna.encode`: it can explode for
        wildcard names. This avoids that problem.
        """
        import idna

        for prefix in [u'*.', u'.']:
            if name.startswith(prefix):
                name = name[len(prefix):]
                return prefix.encode('ascii') + idna.encode(name)
        return idna.encode(name)

def _idna_encode(value):
    # Retain prefixes '*.' for common/alt names and '.' for name constraints
    for prefix in ['*.', '.']:
        if value.startswith(prefix):
            value = value[len(prefix):]
            return prefix + idna.encode(value).decode("ascii")
    return idna.encode(value).decode("ascii")

def idna_encode(name):
        """
        Borrowed wholesale from the Python Cryptography Project. It turns out
        that we can't just safely call `idna.encode`: it can explode for
        wildcard names. This avoids that problem.
        """
        for prefix in [u'*.', u'.']:
            if name.startswith(prefix):
                name = name[len(prefix):]
                return prefix.encode('ascii') + idna.encode(name)
        return idna.encode(name)

def _idna_encode(self, value):
        parsed = urllib_parse.urlparse(value)
        if parsed.port:
            netloc = (
                idna.encode(parsed.hostname) +
                ":{0}".format(parsed.port).encode("ascii")
            ).decode("ascii")
        else:
            netloc = idna.encode(parsed.hostname).decode("ascii")

        # Note that building a URL in this fashion means it should be
        # semantically indistinguishable from the original but is not
        # guaranteed to be exactly the same.
        return urllib_parse.urlunparse((
            parsed.scheme,
            netloc,
            parsed.path,
            parsed.params,
            parsed.query,
            parsed.fragment
        ))

def _encode_general_name(backend, name):
    if isinstance(name, x509.DNSName):
        gn = backend._lib.GENERAL_NAME_new()
        backend.openssl_assert(gn != backend._ffi.NULL)
        gn.type = backend._lib.GEN_DNS

        ia5 = backend._lib.ASN1_IA5STRING_new()
        backend.openssl_assert(ia5 != backend._ffi.NULL)

        if name.value.startswith(u"*."):
            value = b"*." + idna.encode(name.value[2:])
        else:
            value = idna.encode(name.value)

        res = backend._lib.ASN1_STRING_set(ia5, value, len(value))
        backend.openssl_assert(res == 1)
        gn.d.dNSName = ia5
    elif isinstance(name, x509.RegisteredID):
        gn = backend._lib.GENERAL_NAME_new()
        backend.openssl_assert(gn != backend._ffi.NULL)
        gn.type = backend._lib.GEN_RID
        obj = backend._lib.OBJ_txt2obj(
            name.value.dotted_string.encode('ascii'), 1
        )
        backend.openssl_assert(obj != backend._ffi.NULL)
        gn.d.registeredID = obj
    elif isinstance(name, x509.DirectoryName):
        gn = backend._lib.GENERAL_NAME_new()
        backend.openssl_assert(gn != backend._ffi.NULL)

def idna_encode(name):
        """
        Borrowed wholesale from the Python Cryptography Project. It turns out
        that we can't just safely call `idna.encode`: it can explode for
        wildcard names. This avoids that problem.
        """
        import idna

        for prefix in [u'*.', u'.']:
            if name.startswith(prefix):
                name = name[len(prefix):]
                return prefix.encode('ascii') + idna.encode(name)
        return idna.encode(name)