abi

Documentation for eth_defi.abi Python module.

ABI loading from the precompiled bundle.

Provides functions to load ABI files and construct web3.contract.Contract types. The results are cached for the speedup.

We also provide some helper functions to deal with ABI encode/decode.

See Github for available contracts ABI files.

Module Attributes

`ZERO_ADDRESS_STR`	Ethereum 0x0000000000000000000000000000000000000000 address as a string.
`ZERO_ADDRESS`	Ethereum 0x0000000000000000000000000000000000000000 address
`ZERO_ADDRESS_BYTES`	Ethereum 0x address as bytes
`ONE_ADDRESS_STR`	Used by Gnosis Safe in linked lists https://github.com/safe-global/safe-smart-account/pull/993

Functions

`decode_function_args`(func, data)	Decode binary CALL or CALLDATA to a Solidity function,
`decode_function_output`(func, data)	Decode raw return value of Solidity function using Contract proxy object.
`encode_function_call`(func[, args])	Encode function selector + its arguments as data payload.
`encode_multicalls`(funcs)	Encode multiple contract function calls into a single multicall payload for contract built-in multicall functionality.
`encode_with_signature`(function_signature, args)	Mimic Solidity's abi.encodeWithSignature() in Python.
`format_debug_instructions`(bound_call[, ...])	Print curl command line syntax to repeat a failed contract call.
`get_abi_by_filename`(fname)	Reads a embedded ABI file and returns it.
`get_contract`(web3, fname[, bytecode])	Get Contract proxy class from ABI JSON file.
`get_deployed_contract`(web3, fname, address)	Get a Contract proxy objec for a contract deployed at a specific address.
`get_function_abi_by_name`(contract, function_name)	Get function ABI by its name.
`get_function_selector`(func)	Get Solidity function selector.
`get_linked_contract`(web3, fname[, ...])	Create a Contract proxy class from our bundled contracts or filesystem and links it Solidity bytecode.
`get_topic_signature_from_event`(event)	Get topic signature for an Event class.
`get_transaction_data_field`(tx)	Get the "Data" payload of a transaction.
`humanise_decoded_arg_data`(args)	Make decoded arguments more human readable.
`link_libraries_hardhat`(bytecode, ...)	Link Solidity libraries based on Hardhat deployment.
`present_solidity_args`(a)	Try make Solidity call args human readable.

ZERO_ADDRESS_STR = '0x0000000000000000000000000000000000000000'

Ethereum 0x0000000000000000000000000000000000000000 address as a string.

Legacy. Use one below.

ZERO_ADDRESS = '0x0000000000000000000000000000000000000000': Ethereum 0x0000000000000000000000000000000000000000 address

ZERO_ADDRESS_BYTES = b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00': Ethereum 0x address as bytes

ONE_ADDRESS_STR = '0x0000000000000000000000000000000000000001': Used by Gnosis Safe in linked lists https://github.com/safe-global/safe-smart-account/pull/993

get_abi_by_filename(fname)

Reads a embedded ABI file and returns it.

Example:

abi = get_abi_by_filename("ERC20Mock.json")

You are most likely interested in the keys abi and bytecode of the JSON file.

Loaded ABI files are cache in in-process memory to speed up future loading.

Any results are cached.

Parameters

web3 – Web3 instance
fname (str) – JSON filename from supported contract lists.

Returns

Full contract interface, including bytecode.

Return type

dict

get_contract(web3, fname, bytecode=None)

Get Contract proxy class from ABI JSON file.

Read ABI file from - Our bundled contracts in the Python package - Filesystem using absolute path - ABI file can be a solc compiling artifact or Etherscan copy-pasted ABI.

See Web3.py documentation on Contract instances.

Any results are cached. Web3 connection is part of the cache key.

Example:

IERC20 = get_contract(web3, "sushi/IERC20.json")

Parameters

web3 (web3.main.Web3) – Web3 instance
bytecode (Optional[str]) – Override bytecode payload for the contract
fname (str | pathlib.Path) –
Solidity compiler artifact.

Use slash prefixed path for absolute lookups.

JSON filename from supported contract lists.

Returns

Contract proxy class

Return type

Type[web3.contract.contract.Contract]

get_linked_contract(web3, fname, hardhat_export_data=None)

Create a Contract proxy class from our bundled contracts or filesystem and links it Solidity bytecode.

Needed when contracts contain references to libraries. The contract bytecode must be processed and placeholders must be replaced by the on-chain addresses of the deployed library contracts.

Example:

path = self.path.joinpath("artifacts/@aave/core-v3/contracts/mocks/tokens/MintableERC20.sol/MintableERC20.json")
return get_linked_contract(web3, path, get_aave_hardhard_export())

Note

If you do not need linking use get_contract() which is faster.

Parameters

web3 (web3.main.Web3) – Web3 instance
fname (str | pathlib.Path) –
Solidity compiler artifact.

Use slash prefixed path for absolute lookups.

JSON filename from supported contract lists.
hardhat_export_data (Optional[dict]) –
Hardhat deployment export data to link bytecode.

A JSON file generated by hardhat deploy –export command.

Returns

Contract proxy class

Return type

Type[web3.contract.contract.Contract]

get_deployed_contract(web3, fname, address, register_for_tracing=True)

Get a Contract proxy objec for a contract deployed at a specific address.

See Web3.py documentation on Contract instances.

Parameters

web3 (web3.main.Web3) – Web3 instance
fname (str | pathlib.Path) –
JSON filename from supported contract lists.
address (Union[eth_typing.evm.HexAddress, str]) – Ethereum address of the deployed contract
register_for_tracing (bool) – Add the contract to the deployment registry if not already there.

Returns

web3.contract.Contract proxy

Return type

web3.contract.contract.Contract

get_transaction_data_field(tx)

Get the “Data” payload of a transaction.

Ethereum Tester has this in tx.data while Ganache has this in tx.input. Yes, it is madness.

Example:

tx = web3.eth.get_transaction(tx_hash)
function, input_args = router.decode_function_input(get_transaction_data_field(tx))
print("Transaction {tx_hash} called function {function}")

Parameters: tx (web3.datastructures.AttributeDict) –
Return type: str

encode_with_signature(function_signature, args)

Mimic Solidity’s abi.encodeWithSignature() in Python.

This is a Python equivalent for abi.encodeWithSignature().

Example:

payload = encode_with_signature("init(address)", [my_address])
assert type(payload) == bytes

Parameters

function_signature (str) –
Solidity function signature that can be hashed to a selector.

ABI fill be extractd from this signature.
args (Sequence) – Argument values to be encoded.

Return type

bytes

decode_function_output(func, data)

Decode raw return value of Solidity function using Contract proxy object.

Uses web3.Contract.functions prepared function as the ABI source.

Parameters

func (web3.contract.contract.ContractFunction) –
Function which arguments we are going to encode.

Must be bound.
result – Raw encoded Solidity bytes.
data (bytes) –

Return type

Any

encode_function_call(func, args=None)

Encode function selector + its arguments as data payload.

Uses web3.Contract.functions prepared function as the ABI source.

See also encode_function_args().

Example:

Parameters

func (web3.contract.contract.ContractFunction) – Function which arguments we are going to encode.
args (Optional[Sequence]) –
Argument values to be encoded.

If not given, take bound args from the function.

Returns

Solidity’s function selector + argument payload.

Return type

hexbytes.main.HexBytes

decode_function_args(func, data)

Decode binary CALL or CALLDATA to a Solidity function,

Uses web3.Contract.functions prepared function as the ABI source.

Parameters

func (web3.contract.contract.ContractFunction) – Function which arguments we are going to encode.
data (bytes | hexbytes.main.HexBytes) – Extracted from a transaction data field or EVM memoryo trace.

Returns

Ordered dict of the decoded arguments

Return type

dict

humanise_decoded_arg_data(args)

Make decoded arguments more human readable.

All arguments are converted to good text types

See decode_function_args()

Returns: Ordered dict of decoded arguments, easier to read
Parameters: args (dict) –
Return type: dict

link_libraries_hardhat(bytecode, link_references, hardhat_export)

Link Solidity libraries based on Hardhat deployment.

Warning

Preliminary implementation

See get_linked_contract() for details.

Parameters

bytecode (str) –
Raw bytecode of a Solidity contract.

Get from ABI file.

Bytecode must be a in string format, because placeholders are not parseable hex.
link_references (dict) –
List of binary sequences we need to replaced by a contract filename.

Get from ABI file.
hardhat_export (dict) –
Hardhat’s export format.

You get with hardhat deploy –export.

Returns

Linked bytecode

get_function_selector(func)

Get Solidity function selector.

Does not support multiple Solidity functions with the same name, but different arguments. On multiple functions use one first declared in ABI.

Example:

selector = get_function_selector(uniswap_v2.router.functions.swapExactTokensForTokens)
assert selector.hex() == 38ed1739

Parameters

func (web3.contract.contract.ContractFunction) – Unbound or bound contract function proxy

Returns

Solidity function selector.

First 32-bit (4 bytes) keccak hash.

Return type

bytes

get_topic_signature_from_event(event)

Get topic signature for an Event class.

Returns: 0x prefixed hex string
Parameters: event (Type[web3.contract.contract.ContractEvent]) –
Return type: eth_typing.encoding.HexStr

get_function_abi_by_name(contract, function_name)

Get function ABI by its name.

Parameters

contract (web3.contract.contract.Contract) –
function_name (str) –

Return type

dict | None

present_solidity_args(a)

Try make Solidity call args human readable.

Make sure we display bytes as hex.

Example:

contract_address = func_call.address
data_payload = encode_function_call(func_call, func_call.arguments)
logger.info(
    "Lagoon: Wrapping call to TradingStrategyModuleV0. Target: %s, function: %s (0x%s), args: %s, payload is %d bytes",
    contract_address,
    func_call.fn_name,
    get_function_selector(func_call).hex(),
    present_solidity_args(func_call.arguments),
    len(data_payload),
)

Output:

Lagoon: Wrapping call to TradingStrategyModuleV0. Target: 0x5788F91Aa320e0610122fb88B39Ab8f35e50040b, function: exactInput (c04b8d59), args: ["['0x833589fcd6edb6e08f4c7c32d4f71b54bda029130001f442000000000000000000000000000000000000060027106921b130d297cc43754afba22e5eac0fbf8db75b', '0xEBee4d3fE83DD4755761C65b772f6a4f900A118b', '9223372036854775808', '10000000', '25455184317467649376256']"], payload is 324 bytes

Parameters: a (list | tuple | Any) –
Return type: str

format_debug_instructions(bound_call, block_identifier='latest')

Print curl command line syntax to repeat a failed contract call.

Useful for sending information about broken nodes to dRPC team

Parameters: bound_call (web3.contract.contract.ContractFunction) –
Return type: str

encode_multicalls(funcs)

Encode multiple contract function calls into a single multicall payload for contract built-in multicall functionality.

See Uniswap V3 multicall documentation.

Parameters: funcs (list[web3.contract.contract.ContractFunction]) –
Return type: list[bytes]