flask 不停刷新页面，崩溃?报错

我在本地电脑上安装了flask，并且用例子建了一个web服务器，一切正常

我开始玩了,我用浏览器按住F5不停的刷新页面时，flask就崩溃了。

例子：

from flask import Flask
app = Flask(__name__) 

@app.route("/")
def hello():
    return "Hello World!" if __name__ == "__main__":
    app.run()

Traceback (most recent call last):
  File "test.py", line 9, in <module>
    app.run()
  File "D:\Program Files\Python27\lib\site-packages\flask\app.py", line 843, in
run
    run_simple(host, port, self, **options)
  File "D:\Program Files\Python27\lib\site-packages\werkzeug\serving.py", line 6
94, in run_simple
    inner()
  File "D:\Program Files\Python27\lib\site-packages\werkzeug\serving.py", line 6
59, in inner
    srv.serve_forever()
  File "D:\Program Files\Python27\lib\site-packages\werkzeug\serving.py", line 4
99, in serve_forever
    HTTPServer.serve_forever(self)
  File "D:\Program Files\Python27\lib\SocketServer.py", line 238, in serve_forev
er
    self._handle_request_noblock()
  File "D:\Program Files\Python27\lib\SocketServer.py", line 297, in _handle_req
uest_noblock
    self.handle_error(request, client_address)
  File "D:\Program Files\Python27\lib\SocketServer.py", line 295, in _handle_req
uest_noblock
    self.process_request(request, client_address)
  File "D:\Program Files\Python27\lib\SocketServer.py", line 321, in process_req
uest
    self.finish_request(request, client_address)
  File "D:\Program Files\Python27\lib\SocketServer.py", line 334, in finish_requ
est
    self.RequestHandlerClass(request, client_address, self)
  File "D:\Program Files\Python27\lib\SocketServer.py", line 657, in __init__
    self.finish()
  File "D:\Program Files\Python27\lib\SocketServer.py", line 716, in finish
    self.wfile.close()
  File "D:\Program Files\Python27\lib\socket.py", line 283, in close
    self.flush()
  File "D:\Program Files\Python27\lib\socket.py", line 307, in flush
    self._sock.sendall(view[write_offset:write_offset+buffer_size])
socket.error: [Errno 10053]

难道这是bug?