import random
import pycurl
from urllib.parse import urlencode
from io import BytesIO

buff = BytesIO()

boundary = ''
abc = 'qeertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM'
for b in range(16):
    boundary += random.choice(abc)

mime_type = "multipart/form-data; boundary=----WebKitFormBoundary" + boundary
text = """------WebKitFormBoundary%srnContent-Disposition: form-data; name="imgfile";
filename="test.png"rnContent-Type: image/pngrnrnrn------WebKitFormBoundary%s--rn""" % (boundary, boundary)
content_type = 'multipart/form-data; boundary=----WebKitFormBoundary' + boundary
post_data = urlencode({"mimeType": mime_type, "text": text})

headers = {
    'user-agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 '
                  'YaBrowser/17.6.1.776 (beta) Yowser/2.5 Safari/537.36',
    'referer': 'https://s.taobao.com/search?initiative_id=staobaoz_20170719&q=',
    'origin': 'https://s.taobao.com',
    'Expect': '',
    'accept': 'application/json, text/javascript, */*; q=0.01',
    ':scheme': 'https',
    ':path': '/image',
    ':method': 'POST',
    ':authority': 's.taobao.com',
    'x-requested-with': 'XMLHttpRequest',
    'accept-language': 'ru,en;q=0.8',
    'content-type': content_type,
}
headers_list = ["%s: %s" % (n, v) for n, v in headers.items()]
response_headers = []


def header_function(header_line):
    header_line = header_line.decode('iso-8859-1')
    response_headers.append(header_line)

c = pycurl.Curl()
c.setopt(c.URL, 'https://s.taobao.com/image')
c.setopt(c.WRITEDATA, buff)
c.setopt(c.FOLLOWLOCATION, True)
c.setopt(c.VERBOSE, True)
c.setopt(c.POSTFIELDS, post_data)
c.setopt(c.HTTPHEADER, headers_list)
c.setopt(c.HEADERFUNCTION, header_function)
c.setopt(c.HTTPPOST, [
    ('file', (
        c.FORM_FILE, 'test.png',
        c.FORM_FILENAME, 'test.png',
        c.FORM_CONTENTTYPE, 'image/png'
    ))
])

c.perform()
body = buff.getvalue()
print(body.decode())
print(c.getinfo(c.EFFECTIVE_URL))
c.close()

{"status":0,"error":true,"errorCode":"509","errorMsg":"请重新上传试试","extraInfo":""}