Multipart form encoding.

gistfile1.py

import mimetypes

def encode_multipart_formdata(fields=None, files=None):
    """
    fields is a sequence of (name, value) elements for regular form fields.
    files is a sequence of (name, filename, value) elements for data to be uploaded as files
    Return (content_type, body) ready for httplib.HTTP instance
    """
    if not (fields or files):
        return None, None
    BOUNDARY = '----------ThIs_Is_tHe_bouNdaRY_$'
    CRLF = '\r\n'
    L = []
    if fields:
        for (key, value) in fields:
            L.append('--' + BOUNDARY)
            L.append('Content-Disposition: form-data; name="%s"' % key)
            L.append('')
            L.append(value)
    if files:
        for (key, filename, value) in files:
            L.append('--' + BOUNDARY)
            L.append('Content-Disposition: form-data; name="%s"; filename="%s"' % (key, filename))
            L.append('Content-Type: %s' % get_content_type(filename))
            L.append('')
            L.append(value)
    L.append('--' + BOUNDARY + '--')
    L.append('')
    body = CRLF.join(L)
    content_type = 'multipart/form-data; boundary=%s' % BOUNDARY
    return content_type, body


def get_content_type(filename):
    return mimetypes.guess_type(filename)[0] or 'application/octet-stream'