Subtitle downloader

Downloading subtitles for movies can be a trivial task. Just when you found the subtitles the delay is wrong or its in chinese.
Open Subtitles made as service to make this task simple. Hash the file and connect with xmlrpc and open subtitles will find the correct file.
I decieded to make this in python... Just for fun. Here is goes my first python program.

@Parameters
   -f The name of the avi file or directory. If -f is not specified subit will look in the current directory.
   -l A comma delimitered string specifying the language of the subtitles in prioritied order.
   Usage: SubIt.py -f "M:\MyAvis" -l dan,eng

Full source download |  Windows exe download 
		import time
		from array import array
		import struct
		import os
		import urllib
		import sys

		from zipfile import *
		from zipfile import *
		from xmlrpclib import ServerProxy, Error
		from urllib2 import Request, urlopen, URLError, HTTPError
		from optparse import OptionParser 

		server = ServerProxy("http://www.opensubtitles.org/xml-rpc")
		token=""
		def SubIt():
			filename=""
			lang=""
			movieFound=False
			parser = OptionParser() 
			parser.add_option("-f", help="name of the file or directory to get subtitles for. If omitted SubIt will look for .avi files in the current directory",  dest="filename") 
			parser.add_option("-l", help="comma delimitered string with languages. eg dan,eng. If omitted the default will be english", dest="languages") 

			(options, args) = parser.parse_args() 
			
			if options.filename: 
				filename =  options.filename
			if options.languages:  
				lang=options.languages
			else:
				lang="eng"
				
				
			if filename=="" or os.path.isdir(filename) == True:
				if(os.path.isdir(filename) == True):
					directory = filename
				else:
					directory=os.getcwd()
				for root, dirs, files in os.walk(directory):
					for fname in files:
						extension = os.path.splitext( fname )[1]
						if extension==".avi":
							movieFound=True
							FindSubtitles(root +"\\"+ fname,lang) 
						
			else:
				FindSubtitles(filename,lang)
				movieFound=True
			if not movieFound:
				print "No movies found in '"+os.getcwd()+"'"

			raw_input("Done... press enter ")		
		def FindSubtitles(videoname,lang):
			print "Contacting www.opensubtitles.org ("+videoname+")"
			filename = os.path.dirname(videoname) + "\\" +os.path.splitext(os.path.basename(videoname))[0]+ ".srt"
			
			langs=lang.split(",")
			
			data=GetSubtitles(videoname);
			found=False
			if data:
				for l in langs:
					for item in data:
						if item['SubLanguageID']== l and not found:
							print "Found", item['LanguageName'], "subtitle ..."
							zipname=Download(item['ZipDownloadLink'],item['SubFileName'])
							print "Extracting subtitle ",filename
							Unzip(zipname,filename)
							os.remove(zipname)
							found=True
			else:
				print "No Subtitles found"
						
		def GetSubtitles(moviepath	):
			token=server.LogIn("","","","SubIt")["token"]
			
			moviebytesize = os.path.getsize(moviepath) 
			hash=Compute(moviepath)
			movieInfo = {'sublanguageid' : 'all','moviehash' : hash, 'moviebytesize' : moviebytesize}
			movies=[movieInfo]
			data=server.SearchSubtitles(token,movies)['data']
			return data
			
			

		def Compute(name): 
			try:
				longlongformat = 'q'  # long long 
				bytesize = struct.calcsize(longlongformat) 
				f = file(name, "rb") 
				filesize = os.path.getsize(name) 
				hash = filesize 
			                    
				if filesize < 65536 * 2: 
					return "SizeError" 
			                 
				for x in range(65536/bytesize): 
					buffer = f.read(bytesize) 
					(l_value,)= struct.unpack(longlongformat, buffer)  
					hash += l_value 
					hash = hash & 0xFFFFFFFFFFFFFFFF #to remain as 64bit number  

			    
				f.seek(max(0,filesize-65536),0) 
				for x in range(65536/bytesize): 
					buffer = f.read(bytesize) 
					(l_value,)= struct.unpack(longlongformat, buffer)  
					hash += l_value 
					hash = hash & 0xFFFFFFFFFFFFFFFF 

				f.close() 
				returnedhash =  "%016x" % hash 
				return returnedhash 

			except(IOError):
				return "IOError"

		def Unzip(zipname,unzipname):
			z = ZipFile(zipname)
			for filename in z.namelist():
				if os.path.splitext(os.path.basename(filename))[1] == ".srt":
					outfile = file(unzipname, "w")
					outfile.write(z.read(filename))
					outfile.close()
			
		def Download(url,filename):
			req = Request(url)
			f = urlopen(req)
			print "downloading " + url
			# Open our local file for writing
			local_file = open(filename+".zip", "w" + "b")
			#Write to our local file
			local_file.write(f.read())
			local_file.close()
			return filename+".zip"

						
		SubIt()