How to upload files to slack using file.upload and requests

Sending files through http requires a bit more extra work than sending other data. You have to set content type and fetch the file and all that, so you can't just include it in the payload parameter in requests.

You have to give your file information to the files parameter of the .post method so that it can add all the file transfer information to the request.

my_file = {
  'file' : ('/tmp/myfile.pdf', open('/tmp/myfile.pdf', 'rb'), 'pdf')
}

payload={
  "filename":"myfile.pdf", 
  "token":token, 
  "channels":['#random'], 
}

r = requests.post("https://slack.com/api/files.upload", params=payload, files=my_file)