send gasPrice 0 tx

send_tx.py

#!/usr/bin/env python

import argparse
import logging
from web3 import Web3, HTTPProvider

logging.basicConfig(
    format="[%(asctime)s] - %(levelname)s - %(message)s", level=logging.INFO
)


def main():
    parser = argparse.ArgumentParser(
        formatter_class=argparse.ArgumentDefaultsHelpFormatter,
        description="Send ethereum transaction",
    )
    parser.add_argument(
        "--provider",
        default="http://127.0.0.1:8545",
        help="Web3 provider",
    )
    parser.add_argument(
        "--private-key-file",
        default="private_key.json",
        help="Private key file",
    )
    parser.add_argument(
        "--nonce",
        type=int,
        default=0,
        help="nonce",
    )
    parser.add_argument(
        "--count",
        type=int,
        default=10000,
        help="count",
    )
    args = parser.parse_args()

    w3 = Web3(HTTPProvider(args.provider))
    with open(args.private_key_file) as keyfile:
        encrypted_key = keyfile.read()
        private_key = w3.eth.account.decrypt(encrypted_key, "")

    acct = w3.eth.account.from_key(private_key)

    if args.nonce == 0:
        nonce = w3.eth.get_transaction_count(acct.address)
    else:
        nonce = args.nonce

    chain_id = w3.eth.chain_id

    for n in range(0, args.count):
        txn = dict(
            nonce=nonce + n,
            gasPrice=0,
            gas=10240000,
            to=acct.address,
            value=0,
            data=b"1" * 102400,
        )
        signed_txn = w3.eth.account.sign_transaction(txn, private_key)

        txhash = w3.eth.send_raw_transaction(signed_txn.rawTransaction)
        logging.info(f"{txn} -> {txhash.hex()}")


if __name__ == "__main__":
    main()

1. provide a valid private keyfile(password is empty) which contains some Ether
2. execute this python script, eg:

python send_tx.py --private-key-file xxx --provider HTTP://127.0.0.1:8545 --nonce 1 --count 100000

then check the txpool status, you'll see something like this:

$ http :8545 method=txpool_status id=1 jsonrpc=2.0 params:='[]'

{
    "id": "1",
    "jsonrpc": "2.0",
    "result": {
        "pending": "0x2710",
        "queued": "0x0"
    }
}