How to find the minimum in JSON in Python

There is a part of a JSON file:

{
    "payload": {
        "orders": [
            {
                "quantity": 1,
                "platinum": 4,
                "visible": true,
                "order_type": "sell",
                "user": {
                    "reputation": 5,
                    "region": "en",
                    "last_seen": "2022-11-17T08:15:43.360+00:00",
                    "ingame_name": "Noxxat",
                    "id": "5b50d73859d885026b523cd1",
                    "avatar": null,
                    "status": "offline"
                },
                "platform": "pc",
                "region": "en",
                "creation_date": "2020-09-04T15:30:41.000+00:00",
                "last_update": "2021-11-19T09:41:43.000+00:00",
                "id": "5f525da1c98cd000d7513813"
            },
            {
                "order_type": "sell",
                "visible": true,
                "quantity": 2,
                "platinum": 6,
                "user": {
                    "reputation": 3,
                    "region": "en",
                    "last_seen": "2022-11-18T14:22:53.023+00:00",
                    "ingame_name": "Dhatman",
                    "id": "5b79921649262103f74b6585",
                    "avatar": null,
                    "status": "offline"
                },
                "platform": "pc",
                "region": "en",
                "creation_date": "2020-11-06T10:32:32.000+00:00",
                "last_update": "2022-10-11T16:51:55.000+00:00",
                "id": "5fa526406ff3660486ef556c"
            },
            {
                "quantity": 1,
                "visible": true,
                "platinum": 5,
                "order_type": "sell",
                "user": {
                    "reputation": 4,
                    "region": "en",
                    "last_seen": "2022-11-18T18:31:49.199+00:00",
                    "ingame_name": "TheronGuardxx",
                    "avatar": "user/avatar/5e235e94ab7656047a86f70c.png?7b1e90d474a62c6ba3c2d3ef06aed927",
                    "id": "5e235e94ab7656047a86f70c",
                    "status": "offline"
                },
                "platform": "pc",
                "region": "en",
                "creation_date": "2020-12-17T22:46:57.000+00:00",
                "last_update": "2022-10-15T23:37:01.000+00:00",
                "id": "5fdbdfe13e8c4f017f5e3352"
            }
        ]
    }
}

How to find the minimum amount of platinum in this file?
As I understand it, I need to make a loop that will go through the entire file and assign a new value to the variable min if the current amount of platinum is less than the amount currently written in min.

But what should the code look like?

At the moment I have written a block that finds the amount of platinum, the seller’s alias and the number of items from the last element of the JSON-file.

num = 1
flagSell = 0

while flagSell == 0:
    if r_json["payload"]["orders"][len(r_json["payload"]["orders"]) - num]["user"]['status'] == 'ingame':
        if r_json["payload"]["orders"][len(r_json["payload"]["orders"]) - num]["region"] == 'en':
            if r_json["payload"]["orders"][len(r_json["payload"]["orders"]) - num]["order_type"] == 'sell':
                min = r_json["payload"]["orders"][len(r_json["payload"]["orders"]) - num]["platinum"]
                author = r_json["payload"]["orders"][len(r_json["payload"]["orders"]) - num]["user"]["ingame_name"]
                quantity = r_json["payload"]["orders"][len(r_json["payload"]["orders"]) - num]["quantity"]
                flagSell = 1
            else:
                num += 1
        else:
            num += 1
    else:
        num += 1

>Solution :

Try to use bult-in function min() to find minimum order according to the platinum key (data is your dictionary from the question):

min_order = min(data["payload"]["orders"], key=lambda o: o["platinum"])

print("Min Platinum =", min_order["platinum"])
print("Name =", min_order["user"]["ingame_name"])
print("Quantity =", min_order["quantity"])

Prints:

Min Platinum = 4
Name = Noxxat
Quantity = 1

EDIT: If you want to search for a minimum in orders where order_type == 'sell':

min_order = min(
    (o for o in data["payload"]["orders"] if o["order_type"] == "sell"),
    key=lambda o: o["platinum"],
)

print("Min Platinum =", min_order["platinum"])
print("Name =", min_order["user"]["ingame_name"])
print("Quantity =", min_order["quantity"])