# web3-无ABI合约交互

By [Hogen](https://paragraph.com/@hogen) · 2022-06-30

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`格式`

InputData = 0x 60fe47b1 0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000002

InputData = 0x + 4字节函数选择器 + 各32字节Data

`encode 函数选择器`

    bytes4(sha3(“set(uint256)”)) == 0x60fe47b1
    def getFuncHex(funcData):
        k = sha3.keccak_256()
        k.update(funcData.encode('utf-8'))
        return k.hexdigest()[:8]
    

`encode Data`

*   参数转16进制 \[address不用转\]
    

     web3.toHex(value)     
    

*   前面补0,填充满64位\\32字节(bytes32) \[string除外\]
    

    // python
    def to_64(hex):
        zero = ''
        hex = hex[2:]   //去除hex的0x
        zcount = 64-len(hex)
        for i in range(zcount):
            zero += '0'
        return zero+hex
    

*   每个参数拼接到一起
    

实例:
---

    def encodeInputData(funcName,inputArr):
        funcName = ''
        for item in inputArr:
          ---- funcData各种拼接-----
    
        // funcData拼接后 = 'ChangeNum(uint256,address)'
        funcHex = getFuncHex(funcData)
    
    def getFuncHex(funcData):
        k = sha3.keccak_256()
        k.update(funcData.encode('utf-8'))
        return k.hexdigest()[:8]
    

    funcName = 'testEasyInput'
    inputArr = [    {'type':'uint256','value':11},    # {'type':'string','value':'grewgrewgreggreggregreqweeeeeeee'},    # {'type':'address','value':myAddress},    {'type':'uint256','value':22},]
    
    encodeInputData(funcName,inputArr)

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*Originally published on [Hogen](https://paragraph.com/@hogen/web3-abi)*