Getting isMultipartContent = false while using python poster library

Answer 1

If you're on Windows (or a pedant;-), open(filename) is the wrong way to open a binary file and might mess things up -- use open(filename, 'rb'). Apart from that, assuming of course that you continue with a urllib2.urlopen(request) which you've omitted, that your imports are correct, and that filename and url are properly set previously, then your code seems legit.