Upload image through form data using python requests

Question

I am trying to automate uploading of images.

When I upload an image in the browser and look at the network tab I see te following in request body:

------WebKitFormBoundary053SrPeDVvrnxY3c
Content-Disposition: form-data; name="uploadId"
0:0:48deedc5937d0:1009c3
------WebKitFormBoundary053SrPeDVvrnxY3g
Content-Disposition: form-data; name="mtype"
1000
------WebKitFormBoundary053SrPeDVvrnxY3g
Content-Disposition: form-data; name="extensions"
png,gif
------WebKitFormBoundary053SrPeDVvrnxY3g
Content-Disposition: form-data; name="minPixSize"
1000
------WebKitFormBoundary053SrPeDVvrnxY3g
Content-Disposition: form-data; name="maxBytesSize"
1000
------WebKitFormBoundary053SrPeDVvrnxY3g
Content-Disposition: form-data; name="masterSize"
------WebKitFormBoundary053SrPeDVvrnxY3g
Content-Disposition: form-data; name="masterWidth"
------WebKitFormBoundary053SrPeDVvrnxY3g
Content-Disposition: form-data; name="masterHeight"
------WebKitFormBoundary053SrPeDVvrnxY3g
Content-Disposition: form-data; name="imageFile1"; filename="01.jpg"
Content-Type: image/jpeg
------WebKitFormBoundary053SrPeDVvrnxY3g--

How would I repeat such a request with python requests lib?

The problem is the last part:

------WebKitFormBoundary053SrPeDVvrnxY3g
Content-Disposition: form-data; name="imageFile1"; filename="01.jpg"
Content-Type: image/jpeg

All the other fields can just be added as fields in dict passed to data parameter.

So far I tried this:

requests.post(
 url="http://myserver.com/upload",
 headers={
 "Content-Type": "multipart/form-data",
 },
 data={
 "uploadId": "0:0:48deedc5937d0:1009c3",
 "mtype": "1000",
 "extensions": "png,gif",
 "minPixSize": "1000",
 "maxBytesSize": "1000",
 "masterSize": "",
 "masterWidth": "",
 "masterHeight": ""
 },
 files={'media': open("01.jpg", 'rb')}
)

Server responded with:

Could not parse multipart servlet request; nested exception is org.apache.commons.fileupload.FileUploadException: the request was rejected because no multipart boundary was found; id: null

Answer 1

This worked:

import requests
from requests_toolbelt.multipart.encoder import MultipartEncoder
multipart_data = MultipartEncoder(
 fields={
 "uploadId": "0:2d7765623034:557915d737b48:000456",
 "mtype": "1000",
 "extensions": "png,gif",
 "minPixSize": "1000",
 "maxBytesSize": "1000",
 "masterSize": "",
 "masterWidth": "",
 "masterHeight": "",
 "imageFile1": (
 "filename.jpg",
 open("filename.jpg"], 'rb'),
 "image/jpeg"
 )
 }
)
requests.post(
 url="http://myserver.com/upload",
 headers={
 "Content-Type": multipart_data.content_type,
 },
 data=multipart_data,
)