import urllib.request

BROWSER = 'Mozilla/5.0 (Windows NT 5.1; rv:20.0) Gecko/20100101 Firefox/20.0'
URL = 'http://www.cisco.com'

def spoof_firefox():
    opener = urllib.request.build_opener()
	opener.addheaders = [('User-agent', BROWSER)]
	result = opener.open(URL)
	print("Response headers:")
	print(result.headers)
if __name__ == '__main__':
	spoof_firefox()