Python's SimpleHTTPServer not closing the port

SimpleHTTPServer is a useful Python module that allows to start an HTTP server from the current directory. It can be used both on command line:

python -m SimpleHTTPServer

or from within the code:

import SimpleHTTPServer
import SocketServer

Handler = SimpleHTTPServer.SimpleHTTPRequestHandler
httpd = SocketServer.TCPServer(("", PORT), Handler)

print "serving at port", PORT
httpd.serve_forever()

The code above starts the server and binds to PORT number. It can be stopped with CTRL-C. Sometimes SimpleHTTPServer does not release the port it listened on, i.e. it throws Address already in use when run again. It can be fixed with allow_reuse_address option set to True.

...
Handler = SimpleHTTPServer.SimpleHTTPRequestHandler
SocketServer.TCPServer.allow_reuse_address=True
httpd = SocketServer.TCPServer(("", PORT), Handler)
...