Simple example for pass image from pixiv

VkClient.py

import random

import requests
import vk_api
from com.apploidxxx.config import VK_API_KEY as API_KEY
from vk_api.longpoll import VkLongPoll, VkEventType

# Auth as vk group with API key
vk = vk_api.VkApi(token=API_KEY)

# Longpoll for messages
longpoll = VkLongPoll(vk)


def write_msg(user_id: int, message: str) -> None:
    """
    Send message for user
    :param user_id: vk id
    :param message: plain text
    :return: void
    """
    vk.method('messages.send', {'user_id': user_id, 'message': message, 'random_id': random.randint(1, 1000)})


upload = vk_api.VkUpload(vk)

session = requests.Session()

photo = upload.photo_messages(
    photos=session.get(
        'https://i.pximg.net/img-original/img/2018/12/31/19/31/37/72405800_p0.jpg', 
        headers={'Referer': 'https://app-api.pixiv.net/'}, 
        stream=True).raw)

photo_url = 'photo{}_{}'.format(photo[0]['owner_id'], photo[0]['id'])
attachments = [photo_url]

# Main loop - Simple example for work with longpoll
for event in longpoll.listen():

    if event.type == VkEventType.MESSAGE_NEW:

        if event.to_me:

            request = event.text

            if request == "привет":
                attachment = ','.join(attachments)
                vk.method('messages.send', {
                    'user_id': event.user_id,
                    'random_id': random.randint(1, 1000),
                    'attachment': attachment})