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Python library to aid DApp-Server development on VeChain Thor.

Project description

- [Contract](#contract)
- [`get_events(start_block_num, to_block_num, event_id)`](#get_eventsstart_block_num-to_block_num-event_id)
- [FunctionCoder](#functioncoder)
- [`encode_function(function_name, *args)`](#encode_functionfunction_name-args)
- [`decode_result(self, function_name, data)`](#decode_resultself-function_name-data)
- [EventDecoder](#eventdecoder)
- [`decode_event(log)`](#decode_eventlog)

# Contract

```py
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.

```py
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.

```py
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`](#decode_eventlog).<br>
> If you want to get an unsigned transaction data, you can use [`FunctionCoder.encode_function`](#encode_functionfunction_name-args).

# FunctionCoder

```py
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

```py
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


Project details


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