import requests
import json

token = ''
application_id = ''
owner_id_group = ''

payload = {
    'access_token' : token,
    'group_id' : owner_id_group,
    'v' : "5.52"
}

Upload = requests.post('https://api.vk.com/method/photos.getWallUploadServer', data=payload)

img = {'photo': ('Photo.jpg', open(r'Photo.jpg', 'rb'))}

d = Upload.json()

response = requests.post(d['response']['upload_url'], files=img)

response1 = response.json()

loadpay = {
    'access_token' : token,
    'user_id' : owner_id_group,
    'photo' : response1['photo'],
    'server' : response1['server'],
    'hash' : response1['hash']
}

requests.post('https://api.vk.com/method/photos.saveWallPhoto',  data=loadpay)