Python get remote file size function code sharing

def getRemoteFileSize(url, proxy=None):
""" get remote file size via content-length header
url - target file URL
proxy - proxy """
    opener = urllib2.build_opener()
    if proxy:
        if ().startswith('https://'):
            opener.add_handler(({'https' : proxy}))
        else:
            opener.add_handler(({'http' : proxy}))
    try:
        request = (url)
        request.get_method = lambda: 'HEAD'
        response = (request)
        ()
except Exception, e: # The remote file does not exist.
        return 0
    else:
        fileSize = dict().get('content-length', 0)
        return int(fileSize)