7
votes
Accepted
Getting Uniswap v2 latest price and interpreting values using Python
Dev advocate at Chainstack here.
You can get prices directly from the Uniswap V2 pair contract, like you are attempting now, by analyzing the reserves of each token in the pair. The key to obtaining ...
3
votes
How to sign message EIP-712 with whitespace in name?
Metamask's typed-data signing implementation is more permissive than eth-account's encode_structured_data. A new python implementation is in process that will be more compatible with EIP712 signing as ...
- 181
2
votes
Accepted
How to know token transfered in pending status from memepool
You need to decode input params.
You can do this if you know ABI of the smart-contract address.
In your case it is not hard.
Smart contract address: 0xEf1c6E67703c7BD7107eed8303Fbe6EC2554BF6B
ABI (go ...
- 198
2
votes
Calling contract method(0x..) using web3.py
0x0eb0d6a5 looks like a function selector. You can use Contract.get_function_by_selector() to fetch this function using the selector.
2
votes
Sign_transaction and send_raw_transaction error in Web3.py
There are a few issues.
If it's just Python syntax, then you are missing commas and the dictionary for row:
# Fixed commas and row.id and row.trust_value
for row in addresses_df.itertuples():
...
- 1,109
2
votes
Accepted
Manually RLP-encoding an ETH tx gives an incorrect result
You need to convert tx["to"] to bytes before encoding. You also have tx["yParity"] where tx["v"] should be, per your syntax guide.
from rlp import encode
from web3.types ...
- 181
2
votes
Accepted
Decode json.loads(log_event) using python web3
Is there a pre-existing way to do this conversion w/in the web3 library or do I need to create my own converter?
For decoding textual JSON-RPC response, you can reuse the code from web3.py, namely ...
- 22.3k
2
votes
Getting Uniswap v2 latest price and interpreting values using Python
Here is an example how to get the last price on Uniswap v2 compatible DEXes using web3-ethereum-defi Python package.
The PairDetails class will do an automatic conversion of prices to human-readable, ...
- 22.3k
2
votes
Accepted
Cannot create the same ECDSA signature with Web3.py and ethers.js
For ethers.js version 6, the code will be slightly different:
let signer = new ethers.SigningKey(privateKey);
let messageHash = await ethers.solidityPackedKeccak256([ "string", "...
- 1,009
2
votes
Accepted
Good resource for web3 developer
I believe each person have their own style of studying new thing. For my experience here are some good resources and learning path that you can follow:
First, you need to understand the basic of BC ...
- 608
2
votes
Trouble making UniV2 swap on Sepolia with web3py
Because you use function swapETHForExactTokens, thus, you have to define "value" when build_transaction to send ETH with transaction. That why in the transaction hash you can see 0 at value ...
- 608
2
votes
Accepted
Uniswap web3 py buy token fails with execution reverted
This looks like a decent script & it should work. What I'd look for is:
If your account has enough ETH for the swap
If the token that you are trying to get as a result has fees in the contract &...
- 1,109
1
vote
Accepted
Warning! Error encountered during contract execution [execution reverted] when doing a swap using pancakeswap router on bsc testnet
Prior to executing the swap transaction, you need to set the allowance for the router contract to spend WBNB on your behalf.
Here's a quick Python code that shows there's 0 allowance for the router ...
- 1,109
1
vote
How to make contract transactions with Web3.py
It's possible your blockchain doesn't support the Shanghai update. Since solidity v 0.8.20, the compiler implements the new opcode PUSH0, which your blockchain might think it's invalid.
So, change the ...
- 3,139
1
vote
I met difficulties: web3. Exceptions. Web3ValidationError:
When I change the deposit content to “params = ['0xDepositor','0xRecipient', amount_uint256, chainID_uint256, int(relayFeePct_uint64), int(timestamp_uint32), b"", maxCount_uint256]”, it ...
- 11
1
vote
I can´t create a new folder
It is difficult to understand your problem but as i understand your question if you are not able to create folder on remix this is how you can create folder on remix
At the end file you can create ...
- 11
1
vote
contract abi not working if json format
Triple quotes turn your ABI into a string instead of a dictionary. If you want to go the string route, you need to turn the string back into a data structure with something like json.loads (that will ...
- 1,109
1
vote
Accepted
How do I hide or mask the sending address when sending tokens or eth
In order to prevent funds from being easily tracked on the blockchain, you could use a Mixer.
Mixers allow users to deposit an amount of tokens, and then withdraw the tokens from another address that ...
- 1,577
1
vote
SushiSwap contract RouteProcessor: Unknown command code
Route Processor: route breakdown (with working example)
To build a route you'll want to know what you want to do, then look for those stages in the contract.
There are command bytes and pool bytes ...
- 860
1
vote
Problem with web3.py + pyinstaller
Version 6.6.0 had a problem with the necessary json files not being included. If you specify 6.6.1 you should be fine. Support for v5 is due to stop in August.
- 181
1
vote
Accepted
1
vote
How to use signer details from ethers.js to sign transactions with web3.py
You can not use the signer provided by MetaMask to sign transactions without the approval of the user, unlike a signer created using a private key.
1
vote
Accepted
How to decode a log['data'] hexBytes from a solidity event using web3.py
As you can see in the image below the Data field consists of five different attributes and by calling through the below web3 API it returns the hex bytes of those five attributes combined.
w3.eth....
- 93
1
vote
Accepted
Where can I find the ABI for PancakeSwap RouterV2?
You can find the ABI here
Oftentimes smart contracts are verified on block explorers.
- 166
1
vote
Accepted
Can web3.py be used from a server like aws lambda?
Yes, although you would need to store a private key in your lambda. You can use this to retrieve the key securely: https://aws.amazon.com/blogs/compute/securely-retrieving-secrets-with-aws-lambda/
In ...
- 296
1
vote
Accepted
How to get the a block's hash given its number to then feed to filter?
The fromBlock should be a block number, not a block hash, so it have to be like that:
eventFilter = web3.eth.filter(
{"fromBlock": 1000,
"topics": [...
- 668
1
vote
How do I sign a message using web3py?
If you are trying to sign a transaction and interact with a smart contract. You can have a try with the code below
tokenInstance = w3.eth.contract(address="Target Contract Address", abi= &...
- 11
1
vote
Does eth-brownie require using web3py below version 6?
Brownie is no longer very actively maintained and may not work with the latest Web3.py versions.
You might want to migrate to ApeWorX.
- 22.3k
1
vote
processRoute SushiSwap
You say your error is cannot import name 'encode' from 'eth_abi', but in your code you use eth_abi.encode_single which was deprecated so as to not use different code for decoding single vs multiple. ...
- 181
1
vote
Decoding Pending Transaction Input Web3 Python
You are almost there! The main issue is that you are using the wrong contract and tx data in this example.
The transaction you are trying to decode is to PancakeSwap V3, but you are using the V2 ...
Only top scored, non community-wiki answers of a minimum length are eligible