Transaction Module

This module provides the preparatory component that is required for sending a transaction.

with_message(msgs)

This function add one or more messages to <Transaction>

The message can be any message as listed in Oracle Modules or Cosmos Based Messages. Please note that our message should be imported from the generated protobuf files.

Parameter

• msgs <google-protobuf.message.Message>: Messages to be included into the transaction.

Return

• <Transaction>

---

with_sender(client, sender)

This function set account_num and sequence from <Client> with the address from sender. <Transaction> must have at least 1 message added before calling with_sender()

Parameter

• client <Client>: Client used to set account_num and sequence by calling get_address().
• sender <str>: Address of the sender.

Return

• <Transaction>

Exception

Type	Description
EmptyMsgError	Message is empty, please use with_messages at least 1 message
NotFoundError	Account doesn't exist

---

with_account_num(account_num)

This function sets the account number in <Transaction>.

Parameter

• account_num <int>

Return

• <Transaction>

---

with_sequence(sequence)

This function sets the sequence number in <Transaction>.

Parameter

• sequence <int>

Return

• <Transaction>

---

with_chain_id(chain_id)

This function sets the chain ID in <Transaction>.

Parameter

• chain_id <str>

Return

• <Transaction>

---

with_fee(fee)

This function sets the fee by using the given fee and gas limit <Transaction>.

Parameter

• fee <List[Coin]>

Return

• <Transaction>

---

with_gas(gas)

This function sets the gas limit in <Transaction>.

Parameter

• gas <int>

Return

• <Transaction>

---

with_memo(memo)

This function sets the memo in <Transaction>.

Parameter

• memo <str>: Maximum length of memo is 256.

Return

• <Transaction>

Exception

Type	Description
ValueTooLargeError	Memo is too large

---

get_sign_doc(public_key)

This function returns a sign data from <Transaction>.

Parameter

• public_key <PublicKey>, default = None: Public key.

Return

• <cosmos_tx_type.SignDoc>

Exception

Type	Description
EmptyMsgError	message is empty
UndefinedError	account_num should be defined
UndefinedError	sequence should be defined
UndefinedError	chain_id should be defined

---

get_tx_data(signature, public_key)

This function returns a transaction that need to be sent.

Parameter

• signature <bytes>: Signature from sign from get_sign_doc
• public_key <PublicKey, default = None: Public key

Return

• <bytes>

Example use case

Note: Get the <GRPC> here

import os

from pyband.client import Client
from pyband.transaction import Transaction
from pyband.wallet import PrivateKey

from pyband.proto.cosmos.base.v1beta1.coin_pb2 import Coin
from pyband.proto.oracle.v1.tx_pb2 import MsgRequestData

grpc_url = "<GRPC>"
c = Client(grpc_url)

MNEMONIC = os.getenv("MNEMONIC")
private_key = PrivateKey.from_mnemonic(MNEMONIC)
public_key = private_key.to_public_key()
sender_addr = public_key.to_address()
sender = sender_addr.to_acc_bech32()

request_msg = MsgRequestData(
    oracle_script_id=37,
    calldata=bytes.fromhex("0000000200000003425443000000034554480000000000000064"),
    ask_count=4,
    min_count=3,
    client_id="BandProtocol",
    fee_limit=[Coin(amount="100", denom="uband")],
    prepare_gas=50000,
    execute_gas=200000,
    sender=sender,
)

account = c.get_account(sender)
account_num = account.account_number
sequence = account.sequence

fee = [Coin(amount="0", denom="uband")]
chain_id = c.get_chain_id()

txn = (
    Transaction()
    .with_messages(request_msg)
    .with_sequence(sequence)
    .with_account_num(account_num)
    .with_chain_id(chain_id)
    .with_gas(2000000)
    .with_fee(fee)
    .with_memo("")
)

sign_doc = txn.get_sign_doc(public_key)
signature = private_key.sign(sign_doc.SerializeToString())
tx_raw_bytes = txn.get_tx_data(signature, public_key)

print(tx_raw_bytes.hex())

Result

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