https://github.com/iamdefinitelyahuman/eth-event

Tools for Ethereum event decoding and topic generation.
https://github.com/iamdefinitelyahuman/eth-event

ethereum web3py

Last synced: about 14 hours ago
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Tools for Ethereum event decoding and topic generation.

• Host: GitHub
• URL: https://github.com/iamdefinitelyahuman/eth-event
• Owner: iamdefinitelyahuman
• License: mit
• Created: 2019-01-05T21:11:37.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2024-05-21T07:31:05.000Z (5 months ago)
• Last Synced: 2024-09-20T11:07:56.494Z (14 days ago)
• Topics: ethereum, web3py
• Language: Python
• Homepage:
• Size: 126 KB
• Stars: 66
• Watchers: 6
• Forks: 12
• Open Issues: 5
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE

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README

        
# eth-event

[![Pypi Status](https://img.shields.io/pypi/v/eth-event.svg)](https://pypi.org/project/eth-event/) [![Build Status](https://img.shields.io/github/actions/workflow/status/iamdefinitelyahuman/eth-event/main.yaml?branch=master)](https://github.com/iamdefinitelyahuman/eth-event/actions) [![Coverage Status](https://img.shields.io/codecov/c/github/iamdefinitelyahuman/eth-event)](https://codecov.io/gh/iamdefinitelyahuman/eth-event)

Tools for Ethereum event decoding and topic generation.

## Installation

You can install the latest release via `pip`:

```bash

pip install eth-event

```

Or clone the repository and use `setuptools` for the most up-to-date version:

```bash

git clone https://github.com/iamdefinitelyahuman/eth-event.git

cd eth-event

python3 setup.py install

```

## Usage

The public API is well documented within the docstrings. The following example may also help:

```python

>>> from eth_event import get_topic_map

# generating a topic map

>>> abi = open('abi.json').read()

>>> topic_map = get_topic_map(abi)

>>> topic_map

{

    '0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef': {

        'name': 'Transfer',

        'inputs': [

            {'name': 'from', 'type': 'address', 'indexed': True},

            {'name': 'to', 'type': 'address', 'indexed': True},

            {'name': 'value', 'type': 'uint256', 'indexed': False}

        ]

    }

}

# decoding event logs from a transaction receipt

>>> tx = token.transfer(account[1], 100, {'from': account[0]})

>>> eth_event.decode_logs(tx.logs, topic_map)

[{

    'name': 'Transfer',

    'address': "0x3194cBDC3dbcd3E11a07892e7bA5c3394048Cc87",

    'data': [

        {'name': 'from', 'type': 'address', 'value': '0xbd4940951bfa463f8fb6db762e55686f6cfdb73a', 'decoded': True},

        {'name': 'to', 'type': 'address', 'value': '0xbd4940951bfa463f8fb6db762e55686f6cfdb73a', 'decoded': True},

        {'name': 'tokens', 'type': 'uint256', 'value': 100, 'decoded': True}

    ],

    'logIndex': 0,

    'blockNumber': 0,

    'transactionIndex': 0

}]

# decoding a structLog from Geth's debug_traceTransaction endpoint

>>> trace = web3.provider.make_request(

    "debug_traceTransaction",

    ['0x615a157e84715d5f960a38fe2a3ddb566c8393cfc71f15b06170a0eff74dfdde', {}]

)

>>> struct_log = trace['result']['structLogs']

>>> eth_event.decode_trace(struct_log, topic_map, initial_address="0x3194cBDC3dbcd3E11a07892e7bA5c3394048Cc87")

[{

    'name': 'Transfer',

    'address': "0x3194cBDC3dbcd3E11a07892e7bA5c3394048Cc87",

    'data': [

        {'name': 'from', 'type': 'address', 'value': '0xbd4940951bfa463f8fb6db762e55686f6cfdb73a', 'decoded': True},

        {'name': 'to', 'type': 'address', 'value': '0xbd4940951bfa463f8fb6db762e55686f6cfdb73a', 'decoded': True},

        {'name': 'tokens', 'type': 'uint256', 'value': 100, 'decoded': True}

    ],

}]

```

## Limitations

* If an array is indexed in an event, the topic is generated as a sha3 hash and so cannot be decoded. In this case, the undecoded topic is returned and `decoded` is set to `False`.

* Anonymous events cannot be decoded. Use the `allow_undecoded` kwarg when calling `decode_logs` and `decode_trace` to receive the undecoded log without raising an exception.

* When decoding a trace, the initial address for the call cannot be determined. To include addresses where decoded events were emitted you must supply the initial address with the `initial_address` keyword argument.

## Tests

To run the test suite:

```bash

$ tox

```

## Development

This project is still in development. Comments, questions, criticisms and pull requests are welcomed.

## License

This project is licensed under the [MIT license](LICENSE).