Multipart post of image does not get the same result in requests as in Insomnia/Postman

[ClerkCunt]

I am trying to upload a .jpg file to a server using HTTP POST with the requests library in Python 3.7.

Target URL has some PHP code that handles the upload, taking 'fileToUpload' as the multipart variable.

I tried putting the request into a with-statement for opening the file, changing the data=files to files=files (as recommended by some example code), or setting the headers to multipart/form-data specifically.

import requests

url = 'http://someurl.com/upload/dir/post.php'
files = {'fileToUpload' : open('image.jpg', 'rb')}
r = requests.post(url, data=files)

If I run the script I raise every single error message in the post.php file, while if I take the thing to Insomnia or Postman the upload works just fine, so the server-side seems to be working.

After all it seems that the problem is with opening the file, but I tried to stick to the documentation and still can't figure out what is wrong here.

[AndTheDaysGoBy]

Just a thought on how to debug the issue: create a preparedRequest() and then .send() that. If the same behavior arises, then just investigate what's in the prepared request and see if the binary data matches what you wish to send, etc.
This way you might be able to find a cut off point for where the code is either breaking or behaving in a manner you find unexpected.

[samrussell]

Use files, not data:

r = requests.post(url, data=files)

vs

r = requests.post(url, files=files)

[sigmavirus24]

@samrussell is correct