Pyband is a library that is used for interacting with BandChain using gRPC protocol. Querying data and sending transaction can be done here!
This helper library allows users to interact with Bandchain where the following features can be done easily.
- Getting information of a specific oracle script, data source, and request ID.
- Getting the account information of the specify address
- Getting the latest request of the oracle script ID that matches the data and number of validators required to complete the job.
- Getting reference data of pairs of data.
- Seeing all the reporters associated with the specify validator.
- Seeing what Bandchain you are using and getting the latest block in Bandchain.
- Sending transaction in 3 modes, including block mode, async mode, and sync mode.
The library is available on PyPI
pip install pybandBand 2.3.0, Cosmos-SDK 0.44.0, IBC-go 1.1.0
The example code below shows how the library can be used to get the result of the latest request for the price of any cryptocurrency. In this example, we will get the latest price of the following coin - BTC, ETH, MIR, ANC, DOGE, and LUNA. The specified parameters are
oracleScriptID: 37calldata: The hex string representing OBI-encoded value of{'symbols': ['BTC', 'ETH', 'MIR', 'ANC', 'DOGE', 'LUNA'], 'multiplier': 1000000000}minCount: 3askCount: 6
from pyband import Client, PyObi
def main():
grpc_url = "rpc-laozi-testnet2.bandchain.org:9090"
c = Client(grpc_url, insecure=True)
oid = 37
calldata = "000000060000000342544300000003455448000000034d495200000003414e4300000004444f4745000000044c554e41000000003b9aca00"
min_count = 3
ask_count = 6
req_info = c.get_latest_request(oid, calldata, min_count, ask_count)
oracle_script = c.get_oracle_script(oid)
obi = PyObi(oracle_script.schema)
# Convert the calldata to readable syntax
print(obi.decode_input(bytes.fromhex(calldata)))
# Showing the result
print(obi.decode_output(req_info.request.result.result))
if __name__ == "__main__":
main()Here is the result of the program above.
{'symbols': ['BTC', 'ETH', 'MIR', 'ANC', 'DOGE', 'LUNA'], 'multiplier': 1000000000}
{'rates': [31966219600000, 1891714500000, 3280000000, 2012829000, 190938000, 7080000000]}
Another example shows how to send a transaction to Bandchain using block mode.
import os
from pyband import Client, Transaction, PrivateKey
from pyband.proto.cosmos.base.v1beta1.coin_pb2 import Coin
from pyband.proto.oracle.v1.tx_pb2 import MsgRequestData
from google.protobuf.json_format import MessageToJson
def main():
# Step 1 Create a gRPC connection
grpc_url = "rpc-laozi-testnet2.bandchain.org:9090"
c = Client(grpc_url)
# Step 2 Convert a menmonic to private key, public key, and sender
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()
# Step 3 Prepare a transaction's properties
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()
# Step 4 Construct a transaction
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("")
)
# Step 5 Sign a transaction by using private key
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)
# Step 6 Broadcast a transaction
tx_block = c.send_tx_block_mode(tx_raw_bytes)
# Converting to JSON for readability
print(MessageToJson(tx_block))
if __name__ == "__main__":
main()Here is the result after sending a block transaction
{"height":"1136536","txhash":"9B854B9A36A1BFFE3BF16E75E9E8BE2FF5A5D5E4700D17492F3317809527178D","data":"0A090A0772657175657374","rawLog":"[{\"events\":[{\"type\":\"message\",\"attributes\":[{\"key\":\"action\",\"value\":\"request\"}]},{\"type\":\"raw_request\",\"attributes\":[{\"key\":\"data_source_id\",\"value\":\"61\"},{\"key\":\"data_source_hash\",\"value\":\"07be7bd61667327aae10b7a13a542c7dfba31b8f4c52b0b60bf9c7b11b1a72ef\"},{\"key\":\"external_id\",\"value\":\"6\"},{\"key\":\"calldata\",\"value\":\"BTC ETH\"},{\"key\":\"fee\"},{\"key\":\"data_source_id\",\"value\":\"57\"},{\"key\":\"data_source_hash\",\"value\":\"61b369daa5c0918020a52165f6c7662d5b9c1eee915025cb3d2b9947a26e48c7\"},{\"key\":\"external_id\",\"value\":\"0\"},{\"key\":\"calldata\",\"value\":\"BTC ETH\"},{\"key\":\"fee\"},{\"key\":\"data_source_id\",\"value\":\"62\"},{\"key\":\"data_source_hash\",\"value\":\"107048da9dbf7960c79fb20e0585e080bb9be07d42a1ce09c5479bbada8d0289\"},{\"key\":\"external_id\",\"value\":\"3\"},{\"key\":\"calldata\",\"value\":\"BTC ETH\"},{\"key\":\"fee\"},{\"key\":\"data_source_id\",\"value\":\"60\"},{\"key\":\"data_source_hash\",\"value\":\"2e588de76a58338125022bc42b460072300aebbcc4acaf55f91755c1c1799bac\"},{\"key\":\"external_id\",\"value\":\"5\"},{\"key\":\"calldata\",\"value\":\"huobipro BTC ETH\"},{\"key\":\"fee\"},{\"key\":\"data_source_id\",\"value\":\"59\"},{\"key\":\"data_source_hash\",\"value\":\"5c011454981c473af3bf6ef93c76b36bfb6cc0ce5310a70a1ba569de3fc0c15d\"},{\"key\":\"external_id\",\"value\":\"2\"},{\"key\":\"calldata\",\"value\":\"BTC ETH\"},{\"key\":\"fee\"},{\"key\":\"data_source_id\",\"value\":\"60\"},{\"key\":\"data_source_hash\",\"value\":\"2e588de76a58338125022bc42b460072300aebbcc4acaf55f91755c1c1799bac\"},{\"key\":\"external_id\",\"value\":\"4\"},{\"key\":\"calldata\",\"value\":\"binance BTC ETH\"},{\"key\":\"fee\"},{\"key\":\"data_source_id\",\"value\":\"60\"},{\"key\":\"data_source_hash\",\"value\":\"2e588de76a58338125022bc42b460072300aebbcc4acaf55f91755c1c1799bac\"},{\"key\":\"external_id\",\"value\":\"9\"},{\"key\":\"calldata\",\"value\":\"bittrex BTC ETH\"},{\"key\":\"fee\"},{\"key\":\"data_source_id\",\"value\":\"60\"},{\"key\":\"data_source_hash\",\"value\":\"2e588de76a58338125022bc42b460072300aebbcc4acaf55f91755c1c1799bac\"},{\"key\":\"external_id\",\"value\":\"7\"},{\"key\":\"calldata\",\"value\":\"kraken BTC ETH\"},{\"key\":\"fee\"},{\"key\":\"data_source_id\",\"value\":\"60\"},{\"key\":\"data_source_hash\",\"value\":\"2e588de76a58338125022bc42b460072300aebbcc4acaf55f91755c1c1799bac\"},{\"key\":\"external_id\",\"value\":\"8\"},{\"key\":\"calldata\",\"value\":\"bitfinex BTC ETH\"},{\"key\":\"fee\"},{\"key\":\"data_source_id\",\"value\":\"58\"},{\"key\":\"data_source_hash\",\"value\":\"7e6759fade717a06fb643392bfde837bfc3437da2ded54feed706e6cd35de461\"},{\"key\":\"external_id\",\"value\":\"1\"},{\"key\":\"calldata\",\"value\":\"BTC ETH\"},{\"key\":\"fee\"}]},{\"type\":\"request\",\"attributes\":[{\"key\":\"id\",\"value\":\"916006\"},{\"key\":\"client_id\",\"value\":\"BandProtocol\"},{\"key\":\"oracle_script_id\",\"value\":\"37\"},{\"key\":\"calldata\",\"value\":\"0000000200000003425443000000034554480000000000000064\"},{\"key\":\"ask_count\",\"value\":\"4\"},{\"key\":\"min_count\",\"value\":\"3\"},{\"key\":\"gas_used\",\"value\":\"111048\"},{\"key\":\"total_fees\"},{\"key\":\"validator\",\"value\":\"bandvaloper1e9sa38742tzhmandc4gkqve9zy8zc0yremaa3j\"},{\"key\":\"validator\",\"value\":\"bandvaloper19eu9g3gka6rxlevkjlvjq7s6c498tejnwxjwxx\"},{\"key\":\"validator\",\"value\":\"bandvaloper17n5rmujk78nkgss7tjecg4nfzn6geg4cqtyg3u\"},{\"key\":\"validator\",\"value\":\"bandvaloper1zl5925n5u24njn9axpygz8lhjl5a8v4cpkzx5g\"}]}]}]","logs":[{"events":[{"type":"message","attributes":[{"key":"action","value":"request"}]},{"type":"raw_request","attributes":[{"key":"data_source_id","value":"61"},{"key":"data_source_hash","value":"07be7bd61667327aae10b7a13a542c7dfba31b8f4c52b0b60bf9c7b11b1a72ef"},{"key":"external_id","value":"6"},{"key":"calldata","value":"BTC ETH"},{"key":"fee"},{"key":"data_source_id","value":"57"},{"key":"data_source_hash","value":"61b369daa5c0918020a52165f6c7662d5b9c1eee915025cb3d2b9947a26e48c7"},{"key":"external_id","value":"0"},{"key":"calldata","value":"BTC ETH"},{"key":"fee"},{"key":"data_source_id","value":"62"},{"key":"data_source_hash","value":"107048da9dbf7960c79fb20e0585e080bb9be07d42a1ce09c5479bbada8d0289"},{"key":"external_id","value":"3"},{"key":"calldata","value":"BTC ETH"},{"key":"fee"},{"key":"data_source_id","value":"60"},{"key":"data_source_hash","value":"2e588de76a58338125022bc42b460072300aebbcc4acaf55f91755c1c1799bac"},{"key":"external_id","value":"5"},{"key":"calldata","value":"huobipro BTC ETH"},{"key":"fee"},{"key":"data_source_id","value":"59"},{"key":"data_source_hash","value":"5c011454981c473af3bf6ef93c76b36bfb6cc0ce5310a70a1ba569de3fc0c15d"},{"key":"external_id","value":"2"},{"key":"calldata","value":"BTC ETH"},{"key":"fee"},{"key":"data_source_id","value":"60"},{"key":"data_source_hash","value":"2e588de76a58338125022bc42b460072300aebbcc4acaf55f91755c1c1799bac"},{"key":"external_id","value":"4"},{"key":"calldata","value":"binance BTC ETH"},{"key":"fee"},{"key":"data_source_id","value":"60"},{"key":"data_source_hash","value":"2e588de76a58338125022bc42b460072300aebbcc4acaf55f91755c1c1799bac"},{"key":"external_id","value":"9"},{"key":"calldata","value":"bittrex BTC ETH"},{"key":"fee"},{"key":"data_source_id","value":"60"},{"key":"data_source_hash","value":"2e588de76a58338125022bc42b460072300aebbcc4acaf55f91755c1c1799bac"},{"key":"external_id","value":"7"},{"key":"calldata","value":"kraken BTC ETH"},{"key":"fee"},{"key":"data_source_id","value":"60"},{"key":"data_source_hash","value":"2e588de76a58338125022bc42b460072300aebbcc4acaf55f91755c1c1799bac"},{"key":"external_id","value":"8"},{"key":"calldata","value":"bitfinex BTC ETH"},{"key":"fee"},{"key":"data_source_id","value":"58"},{"key":"data_source_hash","value":"7e6759fade717a06fb643392bfde837bfc3437da2ded54feed706e6cd35de461"},{"key":"external_id","value":"1"},{"key":"calldata","value":"BTC ETH"},{"key":"fee"}]},{"type":"request","attributes":[{"key":"id","value":"916006"},{"key":"client_id","value":"BandProtocol"},{"key":"oracle_script_id","value":"37"},{"key":"calldata","value":"0000000200000003425443000000034554480000000000000064"},{"key":"ask_count","value":"4"},{"key":"min_count","value":"3"},{"key":"gas_used","value":"111048"},{"key":"total_fees"},{"key":"validator","value":"bandvaloper1e9sa38742tzhmandc4gkqve9zy8zc0yremaa3j"},{"key":"validator","value":"bandvaloper19eu9g3gka6rxlevkjlvjq7s6c498tejnwxjwxx"},{"key":"validator","value":"bandvaloper17n5rmujk78nkgss7tjecg4nfzn6geg4cqtyg3u"},{"key":"validator","value":"bandvaloper1zl5925n5u24njn9axpygz8lhjl5a8v4cpkzx5g"}]}]}],"gasWanted":"2000000","gasUsed":"564187"}
For more examples, please see example file by running a command python example.py.