python - mattermost api v4 send file into channel

send_file.py

import os
import json
import requests
SERVER_URL = "YOUR_SERVER_URL"
CHANNEL_ID = "YOUR_CHANNEL_ID"
FILE_PATH = './test.jpg'

s = requests.Session()
s.headers.update({"Authorization": "Bearer YOUR_PERSONAL_ACCESS_TOKEN"})

form_data = {
    "channel_id": ('', CHANNEL_ID),
    "client_ids": ('', "id_for_the_file"),
    "files": (os.path.basename(FILE_PATH), open(FILE_PATH, 'rb')),
}
r = s.post(SERVER_URL + '/api/v4/files', files=form_data)

FILE_ID = r.json()["file_infos"][0]["id"]

p = s.post(SERVER_URL + '/api/v4/posts', data=json.dumps({
    "channel_id": CHANNEL_ID,
    "message": "YOUR_MESSAGE",
    "file_ids": [ FILE_ID ]
}))