无法获取交易对的价格

Question

我使用python语言，在python代码中调用web3库来创建智能合约，
连接pancakeswap交易所和BSC链网络，
我想在代码中获取 beth 兑换 usdt 的价格，
我的代码如下，

import time
import json
from web3 import Web3
from web3.middleware import geth_poa_middleware
from datetime import datetime

private_key = "private_key"
address = "address"
bsc_network_url = "https://bsc-dataseed.binance.org/"
pancake_router_address = "0x10ED43C718714eb63d5aA57B78B54704E256024E"
bnb_decimals = 18
usdt_decimals = 6
beth_decimals = 18
sand_decimals = 18
btcb_decimals = 8
xvs_decimals = 18

w3 = Web3(Web3.HTTPProvider(bsc_network_url))
w3.middleware_onion.inject(geth_poa_middleware, layer=0)
if not w3.is_connected():
    raise Exception("Unable to connect to BSC Network")

account = w3.eth.account.from_key(private_key)
my_address = account.address

with open("pancake_router_abi.json", "r") as f:
    router_abi = json.load(f)
pancake_router = w3.eth.contract(address=pancake_router_address, abi=router_abi)

def get_prices_beth_usdt():
    path = [
        w3.to_checksum_address("0x250632378E573c6Be1AC2f97Fcdf00515d0Aa91B"),  # BETH
        w3.to_checksum_address("0x55d398326f99059fF775485246999027B3197955"),  # USDT
    ]
    amount_in = Web3.to_wei(1, 'ether')
    amounts_out = pancake_router.functions.getAmountsOut(amount_in, path).call()
    beth_usdt_price = amounts_out[1] / (10 ** 6)
    return beth_usdt_price

print("BETH/USDT prices:", get_prices_beth_usdt())

这段代码运行后错误如下，如图所示，

是什么原因以及如何解决呢？

Answer 1

运行后错误如下：

Traceback (most recent call last):
  File "jiao_ben_1.py", line 42, in <module>
    print("BETH/USDT prices:", get_prices_beth_usdt())
  File "jiao_ben_1.py", line 38, in get_prices_beth_usdt
    amounts_out = pancake_router.functions.getAmountsOut(amount_in, path).call()
  File "/usr/local/lib/python3.7/dist-packages/web3/contract/contract.py", line 474, in call
    **self.kwargs,
  File "/usr/local/lib/python3.7/dist-packages/web3/contract/utils.py", line 100, in call_contract_function
    ccip_read_enabled=ccip_read_enabled,
  File "/usr/local/lib/python3.7/dist-packages/web3/eth/eth.py", line 255, in call
    return self._durin_call(transaction, block_identifier, state_override)
  File "/usr/local/lib/python3.7/dist-packages/web3/eth/eth.py", line 274, in _durin_call
    return self._call(transaction, block_identifier, state_override)
  File "/usr/local/lib/python3.7/dist-packages/web3/module.py", line 69, in caller
    method_str, params, error_formatters, null_result_formatters
  File "/usr/local/lib/python3.7/dist-packages/web3/manager.py", line 233, in request_blocking
    response, params, error_formatters, null_result_formatters
  File "/usr/local/lib/python3.7/dist-packages/web3/manager.py", line 197, in formatted_response
    apply_error_formatters(error_formatters, response)
  File "/usr/local/lib/python3.7/dist-packages/web3/manager.py", line 73, in apply_error_formatters
    formatted_resp = pipe(response, error_formatters)
  File "cytoolz/functoolz.pyx", line 666, in cytoolz.functoolz.pipe
  File "cytoolz/functoolz.pyx", line 641, in cytoolz.functoolz.c_pipe
  File "/usr/local/lib/python3.7/dist-packages/web3/_utils/method_formatters.py", line 786, in raise_contract_logic_error_on_revert
    raise ContractLogicError("execution reverted", data=data)
web3.exceptions.ContractLogicError: execution reverted