try: import idna as idna2008 except ImportError: idna2008 = None def ascii_bytes(data): if isinstance(data, str): return data.encode('ascii') if isinstance(data, bytes): return data raise TypeError('only str (ascii encoding) and bytes are supported') def maybe_str(data): if isinstance(data, str): return data if isinstance(data, bytes): try: return data.decode('ascii') except UnicodeDecodeError: return data raise TypeError('only str (ascii encoding) and bytes are supported') def is_all_ascii(text): for c in text: if ord(c) > 0x7f: return False return True def parse_name_idna2008(name): parts = name.split('.') r = [] for part in parts: if is_all_ascii(part): r.append(part.encode('ascii')) else: r.append(idna2008.encode(part)) return b'.'.join(r) def parse_name(name): if isinstance(name, str): if is_all_ascii(name): return name.encode('ascii') if idna2008 is not None: return parse_name_idna2008(name) return name.encode('idna') if isinstance(name, bytes): return name raise TypeError('only str and bytes are supported') __all__ = ['ascii_bytes', 'maybe_str', 'parse_name']