How to implement state storage in a chatbot for VK?

Question

Python

It is necessary to write a VK bot for a small camping quest. Mechanics - a person reaches the described point, sends the geolocation, and if it is within the radius of the point, sends the description of the place and the next point.
What is the best way to implement such states in Python?
How can the bot see during message processing that the user sent the card?

Answer 1

https://vk.com/dev/objects/message
You need to parse the message.new event and check for the occurrence of "geo". If "geo" is present in the event, then the geolocation has been sent. Next, you need to process everything that is under the "geo" key.
This is how the message without geolocation looks like:

{
  "type": "message_new",
  "object": {
    "date": 1562246807,
    "from_id": 124239035,
    "id": 18954,
    "out": 0,
    "peer_id": 124239035,
    "text": "Сообщение без геолокации",
    "conversation_message_id": 9652,
    "fwd_messages": [
      
    ],
    "important": false,
    "random_id": 0,
    "attachments": [
      
    ],
    "is_hidden": false
  },
  "group_id": 175820014,
  "secret": "test"
}

And here is the message with geolocation:

{
    "type": "message_new",
    "object":
    {
        "date": 1562246801,
        "from_id": 124239035,
        "id": 18953,
        "out": 0,
        "peer_id": 124239035,
        "text": "Сообщение с геолокацией",
        "conversation_message_id": 9651,
        "fwd_messages": [],
        "important": false,
        "random_id": 0,
        "attachments": [],
        "geo":
        {
            "type": "point",
            "coordinates":
            {
                "latitude": 55.753228,
                "longitude": 37.622511
            },
            "place":
            {
                "country": "Россия",
                "city": "Москва",
                "title": "Москва, Россия"
            }
        },
        "is_hidden": false
    },
    "group_id": 175820014,
    "secret": "test"
}