Issue an HTTP POST request to upload a string as file using libcurl and pycurl. Tested against Python 2.7.3 and libcurl 7.29.0.

pycurl_post_string_as_file.py

#!/usr/bin/env python2
# -*- coding: utf-8 -*-

#
# Issue an HTTP POST request to upload a string as file using libcurl
# and pycurl.
#

# vars.php
# <?php
#   header('Content-Type: text/plain; charset=UTF-8');
#   
#   echo "GET:\n";
#   print_r($_GET);
#   
#   echo "\nPOST:\n";
#   print_r($_POST);
#   
#   echo "\nFILES:\n";
#   print_r($_FILES);
#   
#   foreach ($_FILES as $name => $file) {
#     echo "\nSTART " . $name . "\n";
#     echo file_get_contents($file['tmp_name']);
#     echo "\nEND " . $name . "\n";
#   }
# ?>

import pycurl


def add_str_as_file(form, content, content_type, name, filename):
    e = ('%s"; filename="%s' % (name, filename),
         (pycurl.FORM_CONTENTS, content,
          pycurl.FORM_CONTENTTYPE, content_type,

          # filename={x} above does the trick since this doesn't work
          # pycurl.FORM_FILENAME, filename
          ),
         )

    form.append(e)

data = []

xml = '''<?xml version="1.0" encoding="UTF-8"?>
<message>Здрасти, свят!</message>
<message>Hello, world!</message>'''

add_str_as_file(data, xml, 'application/xml; charset=UTF-8', 'file',
                'universe.xml')

c = pycurl.Curl()
c.setopt(c.URL, 'http://localhost/d/vars.php')
c.setopt(c.HTTPPOST, data)
c.setopt(c.VERBOSE, 1)
# c.setopt(c.PROXY, 'localhost:8008')

c.perform()
c.close()