• Contract
  • get_events(start_block_num, to_block_num, event_id)
• FunctionCoder
  • encode_function(function_name, *args)
  • decode_result(self, function_name, data)
• EventDecoder
  • decode_event(log)

Contract

from vecha import Contract

contract = Contract(endpoint, address, abi_list)

Parameters:

• endpoint: str, thor restful server
• address: str, contract address
• abi_list: List[Dict], contract abi

Then you can call the function directly on the contract instance via the function name in abi.

The get_events function names are built in, so the same name function in the smart contract will not be called.

In a smart contract, the function can be a call or a transaction. A transaction must provide private key.

contract.you_name(*args, caller=None, value=0)  # a call

contract.you_name(*args, pk, value)  # a transaction

You can display the transaction as a call, this may help you debug smart contract.

contract.you_name.call(*args, caller=None, value=0)

get_events(start_block_num, to_block_num, event_id)

Parameters:

• start_block_num (optional): int, default is from genesis block
• to_block_num (optional): int, default is to best block
• event_id (optional): str, the signature of the event you want to filter out, default is all events of this contract

Returns:

• List[Event], A list of Events. Event is a namedtuple, and it has three fields:
  • event.name: str
  • event.args: Dict, actual parameters when the event is emited
  • event.block: int, the block number when the event is emited

If you want to parse a log directly, please use EventDecoder.decode_event.
If you want to get an unsigned transaction data, you can use FunctionCoder.encode_function.

FunctionCoder

from vecha import FunctionCoder

fn_coder = FunctionCoder(*fn_abi_list)

encode_function(function_name, *args)

Parameters:

• function_name: str
• args: variable-length argument list of actual parameters

Returns:

• str, the data of a transaction that has not been signed

decode_result(self, function_name, data)

EventDecoder

from vecha import EventDecoder

ev_decoder = EventDecoder(*event_abi_list)

decode_event(log)

Parameters:

• log: Dict, the result of thor restful api /logs/event

Returns:

• Event, Event is a namedtuple, and it has three fields:
  • event.name: str
  • event.args: Dict, actual parameters when the event is emited
  • event.block: int, the block number when the event is emited