Develop sample

Tags: “Python API” “Quick Install”

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The source code of Python SDK provides a complete Demo for developers to learn

• Call Node API

• Deploy contract, send transaction, process receipt, query contract data

Call Node API

Correct node information configured for SDK connectionRear。Instantiate the client structure in the code and call the client’s interface。Return to json, which can be based on the fisco bcos rpc interface json formatUnderstanding, field fetching and transcoding。

Full Demo: demo_get.py

# Instantiate client
client = BcosClient()

# Call the node version check interface
res = client.getNodeVersion()
print("getClientVersion",res)

# Call the node block high interface
try:
    res = client.getBlockNumber()
    print("getBlockNumber",res)
except BcosError as e:
    print("bcos client error,",e.info())

Operating Contract

Correct node information configured for SDK connectionRear。Can deploy contracts, send transactions, process receipts, and query contract data。For example, call functions such as’ deploy ‘,’ sendRawTransactionGetReceipt ‘,’ call ‘, and’ parse _ event _ logs’。

Full Demo: demo_transaction.py

# Instantiate client
client = BcosClient()

# Load abi definition from file
abi_file  ="contracts/SimpleInfo.abi"
data_parser = DatatypeParser()
data_parser.load_abi_file(abi_file)
contract_abi = data_parser.contract_abi

# Deployment contract
print("\n>>Deploy:---------------------------------------------------------------------")
with open("contracts/SimpleInfo.bin", 'r') as load_f:
    contract_bin = load_f.read()
    load_f.close()
result = client.deploy(contract_bin)
print("deploy",result)
print("new address : ",result["contractAddress"])
contract_name =  os.path.splitext(os.path.basename(abi_file))[0]
memo = "tx:"+result["transactionHash"]
#Save deployment results to file for future reference
from client.contractnote import ContractNote
ContractNote.save_address(contract_name, result["contractAddress"], int(result["blockNumber"], 16), memo)


#Send a transaction, call an interface that overwrites the data
print("\n>>sendRawTransaction:----------------------------------------------------------")
to_address = result['contractAddress'] #use new deploy address
args = ['simplename', 2024, to_checksum_address('0x7029c502b4F824d19Bd7921E9cb74Ef92392FB1c')]

receipt = client.sendRawTransactionGetReceipt(to_address,contract_abi,"set",args)
print("receipt:",receipt)

#Parsing the log in receipt
print("\n>>parse receipt and transaction:----------------------------------------------------------")
txhash = receipt['transactionHash']
print("transaction hash: " ,txhash)
logresult = data_parser.parse_event_logs(receipt["logs"])
i = 0
for log in logresult:
    if 'eventname' in log:
        i = i + 1
        print("{}): log name: {} , data: {}".format(i,log['eventname'],log['eventdata']))
#Obtain the corresponding transaction data and parse the calling method name and parameters

txresponse = client.getTransactionByHash(txhash)
inputresult = data_parser.parse_transaction_input(txresponse['input'])
print("transaction input parse:",txhash)
print(inputresult)

#Parse the output output of the transaction in receipt, that is, the return value of the method called by the transaction
outputresult  = data_parser.parse_receipt_output(inputresult['name'], receipt['output'])
print("receipt output :",outputresult)


#Call to get the data
print("\n>>Call:------------------------------------------------------------------------")
res = client.call(to_address,contract_abi,"getbalance")
print("call getbalance result:",res)
res = client.call(to_address,contract_abi,"getbalance1",[100])
print("call getbalance1 result:",res)
res = client.call(to_address,contract_abi,"getname")
print("call getname:",res)
res = client.call(to_address,contract_abi,"getall")
print("call getall result:",res)
print("demo_tx,total req {}".format(client.request_counter))
client.finish()