python upload file and form

#!/usr/bin/python# demo from here: http://pymotw.com/2/urllib2/index.html#uploading-filesimport itertoolsimport mimetoolsimport mimetypesfrom cStringIO import StringIOimport urllibimport urllib2class MultiPartForm(object):    """Accumulate the data to be used when posting a form."""    def __init__(self):        self.form_fields = []        self.files = []        self.boundary = mimetools.choose_boundary()        return    def get_content_type(self):        return 'multipart/form-data; boundary=%s' % self.boundary    def add_field(self, name, value):        """Add a simple field to the form data."""        self.form_fields.append((name, value))        return    def add_file(self, fieldname, filename, fileHandle, mimetype=None):        """Add a file to be uploaded."""        body = fileHandle.read()        if mimetype is None:            mimetype = mimetypes.guess_type(filename)[0] or 'application/octet-stream'        self.files.append((fieldname, filename, mimetype, body))        return    def __str__(self):        """Return a string representing the form data, including attached files."""        # Build a list of lists, each containing "lines" of the        # request.  Each part is separated by a boundary string.        # Once the list is built, return a string where each        # line is separated by '\r\n'.          parts = []        part_boundary = '--' + self.boundary        # Add the form fields        parts.extend(            [ part_boundary,              'Content-Disposition: form-data; name="%s"' % name,              '',              value,            ]            for name, value in self.form_fields            )        # Add the files to upload        parts.extend(            [ part_boundary,              'Content-Disposition: file; name="%s"; filename="%s"' % \                 (field_name, filename),              'Content-Type: %s' % content_type,              '',              body,            ]            for field_name, filename, content_type, body in self.files            )        # Flatten the list and add closing boundary marker,        # then return CR+LF separated data        flattened = list(itertools.chain(*parts))        flattened.append('--' + self.boundary + '--')        flattened.append('')        return '\r\n'.join(flattened)if __name__ == '__main__':    # Create the form with simple fields    form = MultiPartForm()    form.add_field('userID', '15844444444')    form.add_field('username', '15844444444')    form.add_field('loginToken', 'E02518FFBC69BD82C8A19048CF17A99E')    form.add_field('filetype', 'erp')    # Add a fake file    form.add_file('file', 'data.json',                   fileHandle=StringIO('Python developer and blogger.'))    # Build the request    request = urllib2.Request('127.0.0.1:8080')    request.add_header('User-agent', 'PyMOTW (http://www.doughellmann.com/PyMOTW/)')    body = str(form)    request.add_header('Content-type', form.get_content_type())    request.add_header('Content-length', len(body))    request.add_data(body)    print    print 'OUTGOING DATA:'    print request.get_data()    print    print 'SERVER RESPONSE:'    print urllib2.urlopen(request).read()