crawl_bnb_transaction.py

crawl_bnb_transaction.py

import datetime
import concurrent.futures
from collections import namedtuple

BNB_transaction = namedtuple('BNB_transactions', ['hash', 'created_at', 'block', 'from_address', 'to_address', 'amount'])

def get_receipt(tx):
    if isinstance(tx, AttributeDict):
        tx = tx.hash
    return web3.eth.getTransactionReceipt(tx)

def get_address_from_topic(topic):
    hex40 = web3.toHex(topic)[-40:]
    address = web3.toChecksumAddress(hex40)
    return address


def get_balance_from_data(data):
    wei_balance = web3.toInt(hexstr=data)
    ether_balance = web3.fromWei(wei_balance, 'ether')
    return ether_balance
    
def crawler(height):
    # Get transactions from block
    block = web3.eth.getBlock(height, full_transactions=True)
    block_timestamp = datetime.datetime.fromtimestamp(block.timestamp)
    
    # Get receipt of each transaction
    receipts = []
    with concurrent.futures.ThreadPoolExecutor() as executor:
        for receipt in executor.map(get_receipt, block.transactions):
            receipts.append(receipt)
    
    # Error Handling
    if len(receipts) != len(block.transactions):
        raise Exception("Receipt count not equal")

    if any(receipt is None for receipt in receipts):
        raise Exception("Some receipt is None")
    
    # Parse BNB transaction
    bnb_transactions = []
    for receipt in receipts:
        if not receipt.logs: # logs may be None
            continue
            
        for log in receipt.logs:
            if not (log.address and
                    web3.toChecksumAddress(log.address) == BNB_ADDRESS and
                    web3.toHex(log.topics[0]) == TRANSFER_LOG_HASH):
                continue
                
            bnb_transactions.append(BNB_transaction(
                hash=web3.toHex(receipt.transactionHash),
                created_at=block_timestamp,
                block=height, 
                from_address=get_address_from_topic(log.topics[1]),
                to_address=get_address_from_topic(log.topics[2]),
                amount=get_balance_from_data(log.data),
            ))
    
    return bnb_transactions

crawler(6259346)

''' Output
[BNB_transactions(
   hash='0xba48fc0e658bfd927370ae0dda6fd37793e504e90289cd8216e986ebf714699b', 
   created_at=datetime.datetime(2018, 9, 3, 0, 20, 10), 
   block=6259346, 
   from_address='0x98702707fe04c38CE752aFad9C392f4A46289274', 
   to_address='0x3f5CE5FBFe3E9af3971dD833D26bA9b5C936f0bE', 
   amount=Decimal('8.5')
)]
'''