python之运行 python manage.py 时出错

我在 Ubuntu 中使用 flask，当我运行 python manage.py 时，我得到了这个 Traceback:

Traceback (most recent call last): 
  File "manage.py", line 8, in <module> 
    app.run(debug=True,processes=True) 
  File "/proj/local/lib/python2.7/site-packages/flask/app.py", line 772, in run 
    run_simple(host, port, self, **options) 
  File "/proj/local/lib/python2.7/site-packages/werkzeug/serving.py", line 671, in run_simple 
    s.bind((hostname, port)) 
  File "/usr/lib/python2.7/socket.py", line 224, in meth 
    return getattr(self._sock,name)(*args) 
socket.error: [Errno 98] Address already in use