web3py ValidationError

Question

import json
from web3 import Web3

mainnet_infura_url = '????'
web3 = Web3(Web3.HTTPProvider(mainnet_infura_url)) 
res = web3.isConnected()
print(res)

#mainnet
weth_token = '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2'
wbtc_token =  '0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599'


uniswap_v3_quoter_abi = json.loads('[{"inputs":[{"internalType":"address","name":"_factory","type":"address"},{"internalType":"address","name":"_WETH9","type":"address"}],"stateMutability":"nonpayable","type":"constructor"},{"inputs":[],"name":"WETH9","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"factory","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"bytes","name":"path","type":"bytes"},{"internalType":"uint256","name":"amountIn","type":"uint256"}],"name":"quoteExactInput","outputs":[{"internalType":"uint256","name":"amountOut","type":"uint256"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"tokenIn","type":"address"},{"internalType":"address","name":"tokenOut","type":"address"},{"internalType":"uint24","name":"fee","type":"uint24"},{"internalType":"uint256","name":"amountIn","type":"uint256"},{"internalType":"uint160","name":"sqrtPriceLimitX96","type":"uint160"}],"name":"quoteExactInputSingle","outputs":[{"internalType":"uint256","name":"amountOut","type":"uint256"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes","name":"path","type":"bytes"},{"internalType":"uint256","name":"amountOut","type":"uint256"}],"name":"quoteExactOutput","outputs":[{"internalType":"uint256","name":"amountIn","type":"uint256"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"tokenIn","type":"address"},{"internalType":"address","name":"tokenOut","type":"address"},{"internalType":"uint24","name":"fee","type":"uint24"},{"internalType":"uint256","name":"amountOut","type":"uint256"},{"internalType":"uint160","name":"sqrtPriceLimitX96","type":"uint160"}],"name":"quoteExactOutputSingle","outputs":[{"internalType":"uint256","name":"amountIn","type":"uint256"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"int256","name":"amount0Delta","type":"int256"},{"internalType":"int256","name":"amount1Delta","type":"int256"},{"internalType":"bytes","name":"path","type":"bytes"}],"name":"uniswapV3SwapCallback","outputs":[],"stateMutability":"view","type":"function"}]')

uniswap_v3_quoter_address = '0xb27308f9F90D607463bb33eA1BeBb41C27CE5AB6'
uniswap_v3_quoter_contract = web3.eth.contract(address = uniswap_v3_quoter_address, abi = uniswap_v3_quoter_abi)

uniswap_v3_quoter_contract.functions.quoteExactInputSingle(
    wbtc_token, weth_token, web3.toWei(0.01, 'ether'), 3000, 0).call()

它给出了错误

---------------------------------------------------------------------------
ValidationError                           Traceback (most recent call last)
Input In [1], in <cell line: 25>()
     21 uniswap_v3_quoter_contract = web3.eth.contract(address = uniswap_v3_quoter_address, abi = uniswap_v3_quoter_abi)
     23 int(web3.toWei(0.01, 'ether'))
---> 25 uniswap_v3_quoter_contract.functions.quoteExactInputSingle(
     26     wbtc_token, weth_token, web3.toWei(0.01, 'ether'), 3000, 0).call()

File ~/miniconda3/envs/web3/lib/python3.9/site-packages/web3/contract.py:878, in ContractFunction.__call__(self, *args, **kwargs)
    876 else:
    877     clone.kwargs = kwargs
--> 878 clone._set_function_info()
    879 return clone

File ~/miniconda3/envs/web3/lib/python3.9/site-packages/web3/contract.py:883, in ContractFunction._set_function_info(self)
    881 def _set_function_info(self) -> None:
    882     if not self.abi:
--> 883         self.abi = find_matching_fn_abi(
    884             self.contract_abi,
    885             self.web3.codec,
    886             self.function_identifier,
    887             self.args,
    888             self.kwargs
    889         )
    890     if self.function_identifier in [FallbackFn, ReceiveFn]:
    891         self.selector = encode_hex(b'')

File ~/miniconda3/envs/web3/lib/python3.9/site-packages/web3/_utils/contracts.py:163, in find_matching_fn_abi(abi, abi_codec, fn_identifier, args, kwargs)
    143     diagnosis = (
    144         "\nAmbiguous argument encoding. "
    145         "Provided arguments can be encoded to multiple functions matching this call."
    146     )
    148 message = (
    149     "\nCould not identify the intended function with name `{name}`, "
    150     "positional argument(s) of type `{arg_types}` and "
   (...)
    160     diagnosis=diagnosis,
    161 )
--> 163 raise ValidationError(message)

ValidationError: 
Could not identify the intended function with name `quoteExactInputSingle`, positional argument(s) of type `(<class 'str'>, <class 'str'>, <class 'int'>, <class 'int'>, <class 'int'>)` and keyword argument(s) of type `{}`.
Found 1 function(s) with the name `quoteExactInputSingle`: ['quoteExactInputSingle(address,address,uint24,uint256,uint160)']
Function invocation failed due to no matching argument types.

我真的搞不懂到底是怎么回事

Answer 1

看起来您使用的web3.eth.contract方法不正确。address参数应该作为关键字参数传递，如下所示：

uniswap_v3_quoter_contract = web3.eth.contract(
    address=uniswap_v3_quoter_address, 
    abi=uniswap_v3_quoter_abi
)

此外，看起来您试图在不发送事务的情况下调用合同上的函数。为了调用契约上的函数，需要对函数对象使用call()方法，如下所示：

amount_out = uniswap_v3_quoter_contract.functions.quoteExactInputSingle(
    wbtc_token, weth_token, web3.toWei(0.01, 'ether'), 3000, 0
).call()

这将调用函数并返回结果，但它不会发送事务，因此不会更改合同的状态。如果要发送事务并更改合同状态，则需要对函数对象使用sendTransaction()方法。该方法将事务对象作为参数，该参数包含有关事务的信息，如from地址、气体限制和天然气价格。例如：

tx = {
    'from': '0xYOUR_ADDRESS',
    'gas': 1000000,
    'gasPrice': web3.toWei('1', 'gwei')
}

tx_hash = uniswap_v3_quoter_contract.functions.quoteExactInputSingle(
    wbtc_token, weth_token, web3.toWei(0.01, 'ether'), 3000, 0
).sendTransaction(tx)

这将发送一个事务并更改合同的状态，但它不会返回函数调用的结果。相反，它将返回发送的事务的事务哈希。然后，您可以使用此事务哈希来跟踪事务，并在挖掘后获得结果。

希望这能有所帮助！

Answer 2

由于ABI解码错误，此调用失败。通过将数据作为tuple()传递，可以避免此错误。

替换

    amount_out = uniswap_v3_quoter_contract.functions.quoteExactInputSingle(
        wbtc_token, weth_token, eth_client.toWei(0.01, 'ether'), 3000, 0
    ).call()

使用

    amount_out = uniswap_v3_quoter_contract.functions.quoteExactInputSingle(
        (wbtc_token, weth_token, eth_client.toWei(0.01, 'ether'), 3000, 0)
    ).call()

否则，您将遇到此异常：

web3.exceptions.ValidationError: 
Could not identify the intended function with name `quoteExactInputSingle`, positional argument(s) of type `(<class 'str'>, <class 'str'>, <class 'int'>, <class 'int'>, <class 'int'>)` and keyword argument(s) of type `{}`.
Found 1 function(s) with the name `quoteExactInputSingle`: ['quoteExactInputSingle(tuple)']
Function invocation failed due to improper number of arguments

您可以通过函数签名'quoteExactInputSingle(tuple)'告诉函数接受元组。

您可以在元组中看到函数所期望的内容，查看以太扫描上的quoterv2代码。https://etherscan.io/address/0x61fFE014bA17989E743c5F6cB21bF9697530B21e#code

    function quoteExactInputSingle(QuoteExactInputSingleParams memory params)
        public
        override
        returns (
            uint256 amountOut,
            uint160 sqrtPriceX96After,
            uint32 initializedTicksCrossed,
            uint256 gasEstimate
        )

当您查看QuoteExactInputSingleParams结构时。

QuoteExactInputSingleParams({
                        tokenIn: tokenIn,
                        tokenOut: tokenOut,
                        fee: fee,
                        amountIn: amountIn,
                        sqrtPriceLimitX96: 0
                    }

因此，它必须是一个元组，并按列出的顺序排列5个参数。