Function invocation failed due to no matching argument type. web3.py, Python

Question

I'm trying to swap tokens using swapExactTokensForTokens() (Pancakeswap Router function).

Here is my code

def swapTokens():
    amountIn = (w3.toWei(0.00001, 'ether'))
    amount1 = contractR.functions.getAmountsOut(
        amountIn,
        [wbnb, tokenToBuy]
    ).call()
    amountOutMin = amount1[1] * 0.9
    minAmountPrint = w3.fromWei(amountOutMin, 'ether')
    print('Minimum recieved:', minAmountPrint)

    swap_TX = contractR.functions.swapExactTokensForTokens(
        amountIn,
        amountOutMin,
        [wbnb, tokenToBuy],
        myAccount,
        (int(time.time()) + 1000000)
    ).buildTransaction({
        'from': myAccount,
        'value': w3.toWei(0.0001, 'ether'),
        'gas': 250000,
        'gasPrice': w3.toWei('5', 'gwei'),
        'nonce': nonce,
    })
    signed_TX = w3.eth.account.sign_transaction(swap_TX, private_key=privateKey)
    tx_token = w3.eth.send_raw_transaction(signed_TX.rawTransaction)
    print(w3.toHex(tx_token))

But i keep getting error as the result:

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

I checked type of every argument passed to the function and thy matched.

the second argument u passed is type 'float' instead of 'int'. could that be the problem? — richie, Jun 02 '21 at 16:46
that was the problem. Thanks! Btw transaction failed. By any chance do you know a service that cna help me to figure out at what step of the tx it failed? — Samuel Alibien, Jun 02 '21 at 19:11
hey @richie, since that was it, maybe consider posting your somment as an answer so the OP can accept it for that sweet +10 reputation :b — jemand771, Jun 02 '21 at 19:59
can u edit the question with the other problems details or open a new post with it? — richie, Jun 02 '21 at 20:38

score 3 · Accepted Answer · answered Jun 02 '21 at 20:36

3

the second argument u passed is type 'float' instead of the required 'int'.

answered Jun 02 '21 at 20:36

richie

181
5

score 2 · Answer 2 · answered Jan 30 '22 at 07:41

I've just solved a similar problem, and it took me more than 3 hours to figure out that: if your address has one space at the beginning or the end, then it is not an address and you will get the error No matching argument type. But the point is, I've never thought that a space can take me 3 hours. So, check your address if there is any space in it.

score 0 · Answer 3 · answered Nov 17 '21 at 20:37

0

Make sure there are no double quotes " in addresses.

[wbnb.strip('"'), tokenToBuy.strip('"')]

answered Nov 17 '21 at 20:37

Danil

4,781
1
35
50

Function invocation failed due to no matching argument type. web3.py, Python

3 Answers3