updated tcp_charfinder.py to Python 3.8 asyncio API

Author: ramalho

18-asyncio-py3.7/charfinder/tcp_charfinder.py

@@ -38,26 +38,17 @@ async def handle_queries(reader, writer): # <3>
 # END TCP_CHARFINDER_TOP
 
 # BEGIN TCP_CHARFINDER_MAIN
-def main(address='127.0.0.1', port=2323): # <1>
+async def main(address='127.0.0.1', port=2323): # <1>
  port = int(port)
- loop = asyncio.get_event_loop()
- server_coro = asyncio.start_server(handle_queries, address, port,
- loop=loop) # <2>
- server = loop.run_until_complete(server_coro) # <3>
+ server = await asyncio.start_server(handle_queries, address, port) # <2>
 
- host = server.sockets[0].getsockname() # <4>
- print('Serving on {}. Hit CTRL-C to stop.'.format(host)) # <5>
- try:
- loop.run_forever() # <6>
- except KeyboardInterrupt: # CTRL+C pressed
- pass
+ host = server.sockets[0].getsockname() # <3>
+ print('Serving on {}. Hit CTRL-C to stop.'.format(host)) # <4>
 
- print('Server shutting down.')
- server.close() # <7>
- loop.run_until_complete(server.wait_closed()) # <8>
- loop.close() # <9>
+ async with server:
+ await server.serve_forever()
 
 
 if __name__ == '__main__':
- main(*sys.argv[1:]) # <10>
+ asyncio.run(main(*sys.argv[1:])) # <5>
 # END TCP_CHARFINDER_MAIN