Using Pytezos to Properly call a smart contract with correct parameters ( to purchase token from objkt )

Question

I am hitting a wall trying to figure out a working proof of concept to get pytezos to "purchase" a token from objkt. I am using the following script with pytezos under the assumption that:

1. I do this using an operation group
2. I should use the .transaction method
3. I need to pass the entrypoint ( in tzKT this appears to be a fulfill_ask entrypoint? ) and the additional token_id?

from pytezos import pytezos
from decimal import Decimal


# COLECT THIS TOKEN: https://objkt.com/asset/KT1KXXZ758wtyf2NBjWKPeXugDh5Mm7kyckw/2
# COLLECTIO CONTRACT: KT1KXXZ758wtyf2NBjWKPeXugDh5Mm7kyckw
# Market PLace Contract: KT1WvzYHCNBvDSdwafTHv7nJ1dWmZ8GCYuuC
# PRICE: Decimal('.01')
# CREATOR: tz2SRxyGc1SFnbAyGuWTNcRbWgZB6pyeGYqB


PRVKEY = "edsk...."
contract_address='KT1WvzYHCNBvDSdwafTHv7nJ1dWmZ8GCYuuC'
token_id=2
ask_id = 1253832

opgrp = pytezos.using( shell='mainnet', key=PRVKEY )

# best guess how to format parameters based on doc: https://pytezos.org/high_level.html#pytezos.client.PyTezosClient.transaction


opg2 = opg.transaction( destination=contract_address, 
                        amount=Decimal('.009'), 
                        fee=Decimal('.00150'), 
                        parameters  = { "entrypoint": 'fulfill_ask', 
                                        "value": '(Pair ask_id {})'.format(ask_id) })  


opgrp2 = opgrp2.fill()
opgrpSigned = opgrp2.sign() # error out here: fails to parse the Micheline expression for "value"

UPDATED: User iguerNL pointed out the flaw that i am not connecting with the correct contract, i am updating to fix that.

Answer 1

Your destination contract doesn't seem to have a fulfill_ask entrypoint.

https://tzkt.io/KT1KXXZ758wtyf2NBjWKPeXugDh5Mm7kyckw/entrypoints

And according to betterCallDev, there is no deployed Tezos contract with a fulfill_ask entrypoint (?):

https://better-call.dev/search?text=fulfill_ask

Answer 2

Instead of doing the low-level stuff yourself, you may consider trying to use factori, see the Python section of the recent article https://functori.com/blog/blog-csharp-python-now-supported-in-factori.html . You can adapt the given scenario to call your contract.

If the following scenario isn't clear, please ask and I will explain it more in detail:

Can you try this (with the right identity, that is, instead of Alice, input your secret key and your public key)?

First get factori using e.g. docker as in https://gitlab.com/functori/dev/factori/-/blob/next/README.md . Then:

mkdir test && cd test
factori import kt1 . KT1WvzYHCNBvDSdwafTHv7nJ1dWmZ8GCYuuC --name test --python --force

Create a file src/python_sdk/main.py:

from importlib.metadata import metadata
import time
import test_python_interface
import factori_types
import blockchain

def main():
    debug = False
    kt1 = "KT1WvzYHCNBvDSdwafTHv7nJ1dWmZ8GCYuuC"
    #modify your script with the right identity
    alice : blockchain.identity = { 'sk' : "edsk3QoqBuvdamxouPhin7swCvkQNgq4jP5KZPbwWNnwdZpSpJiEbq", 'pk' : 'edpkvGfYw3LyB1UcCahKQk4rF2tvbMUk8GFiTuMjL75uGXrpvKXhjn', 'pkh' : 'tz1VSUr8wwNhLAzempoch5d6hLRiTh8Cjcjb' }
    ask_id = 1253832
    param : Fulfill_ask = {"ask_id" : ask_id, "proxy" : None}
    ophash = test_python_interface.callFulfill_ask (
        kt1,
        _from=alice,
        param=param,
        networkName="mainnet",
        debug=debug,
    )
    print("An operation is sent to a node. Its hash is: " + ophash)
    print("Waiting for its inclusion in a block ...")
    time.sleep(15)  # we need to wait for one block before calling the contract
    print("Check the status of your operation: https://tzkt.io/" + ophash)

main()

Finally, run

python3 src/python_sdk/main.py