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我使用 web3.py 读取大量数据，我看不出这里出了什么问题。getValue()和getValue2()，都可以从remix.ethereum.org调用没有错误，但是当我使用我贴的python代码时，只能读出getValue2()，函数getValue()抛出错误看起来它在气体限制中运行。但是由于该函数不会引发从 remix.ethereum 调用的错误，我真的不明白为什么会有这样的气体错误：

Solidity 合约：

pragma solidity ^0.4.19;


contract TestContract {

   uint [1000000] val;
   uint [200000] val2;


   function TestContract(){

   }

   function getValue()  external view returns(uint [1000000]){
         return val;
   }

   function getValue2()  external view returns(uint [200000]){
         return val2;
   }
}

Python代码：

import json
import web3

from web3 import Web3, HTTPProvider
from web3.contract import ConciseContract

# web3
w3 = Web3(HTTPProvider('https://ropsten.infura.io'))

# Instantiate and deploy contract
contractAddress = '0x37c587c2174bd9248f203947d7272bf1b8f91fa9'

with open('testfactory.json', 'r') as abi_definition:
    abi = json.load(abi_definition)

contract_instance = w3.eth.contract(contractAddress, abi=abi,ContractFactoryClass=ConciseContract)

arr2=contract_instance.getValue2() #works fine
print(len(arr2))

arr=contract_instance.getValue() #throws an error, posted below
print(len(arr))

测试工厂.json：

[
    {
        "constant": true,
        "inputs": [],
        "name": "getValue2",
        "outputs": [
            {
                "name": "",
                "type": "uint256[200000]"
            }
        ],
        "payable": false,
        "stateMutability": "view",
        "type": "function"
    },
    {
        "constant": true,
        "inputs": [],
        "name": "getValue",
        "outputs": [
            {
                "name": "",
                "type": "uint256[1000000]"
            }
        ],
        "payable": false,
        "stateMutability": "view",
        "type": "function"
    },
    {
        "inputs": [],
        "payable": false,
        "stateMutability": "nonpayable",
        "type": "constructor"
    }
]

pyton 中的错误：

Traceback (most recent call last):
  File "C:\Python36\lib\site-packages\web3\contract.py", line 844, in call_contract_function
    output_data = decode_abi(output_types, return_data)
  File "C:\Python36\lib\site-packages\eth_abi\abi.py", line 109, in decode_abi
    return decoder(stream)
  File "C:\Python36\lib\site-packages\eth_abi\decoding.py", line 102, in __call__
    return self.decode(stream)
  File "C:\Python36\lib\site-packages\eth_utils\functional.py", line 22, in inner
    return callback(fn(*args, **kwargs))
  File "C:\Python36\lib\site-packages\eth_abi\decoding.py", line 140, in decode
    yield decoder(stream)
  File "C:\Python36\lib\site-packages\eth_abi\decoding.py", line 102, in __call__
    return self.decode(stream)
  File "C:\Python36\lib\site-packages\eth_utils\functional.py", line 22, in inner
    return callback(fn(*args, **kwargs))
  File "C:\Python36\lib\site-packages\eth_abi\decoding.py", line 198, in decode
    yield cls.item_decoder(stream)
  File "C:\Python36\lib\site-packages\eth_abi\decoding.py", line 102, in __call__
    return self.decode(stream)
  File "C:\Python36\lib\site-packages\eth_abi\decoding.py", line 165, in decode
    raw_data = cls.read_data_from_stream(stream)
  File "C:\Python36\lib\site-packages\eth_abi\decoding.py", line 247, in read_data_from_stream
    len(data),
eth_abi.exceptions.InsufficientDataBytes: Tried to read 32 bytes.  Only got 0 bytes

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:/Users/Sebi/PycharmProjects/web3/test.py", line 18, in <module>
    arr=contract_instance.getValue()
  File "C:\Python36\lib\site-packages\web3\contract.py", line 805, in __call__
    return self.__prepared_function(**kwargs)(*args)
  File "C:\Python36\lib\site-packages\web3\contract.py", line 866, in call_contract_function
    raise_from(BadFunctionCallOutput(msg), e)
  File "C:\Python36\lib\site-packages\web3\utils\exception_py3.py", line 2, in raise_from
    raise my_exception from other_exception
web3.exceptions.BadFunctionCallOutput: Could not decode contract function call getValue return data 0x for output_types ['uint256[1000000]']

有什么建议我能做什么？web3.py v4.0 中是否存在错误？

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0 回答 0