请教一下, 在CTA策略中，
定义了实例变量
def on_init(self):
self.buy_price = 0.0
self.sell_price = 0.0
def on_tick(self, tick: TickData) -> None:
self.buy_price = tick.bid_price_1
self.sell_price = tick.ask_price_1
在bar环节调用，仍然报错
def on_15min_bar(self, bar: BarData):
if self.pos == 0:
self.buy(buy_price , fixed_size)
报错如下：AttributeError: 'MA_logtest' object has no attribute 'buy_price'。
请问是什么原因？

贴一下完整报错截图吧

在on_15min_bar环节打印测试了一下，没有
2025-07-23 10:16:28.005 | INFO | CtaStrategy | [MA_logtest] 触发异常已停止
Traceback (most recent call last):
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy_ctastrategy/engine.py", line 619, in call_strategy_func
func()
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy_ctastrategy/strategies/MA_15min.py", line 108, in on_init
self.load_bar(
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy_ctastrategy/template.py", line 308, in load_bar
callback(bar)
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy_ctastrategy/strategies/MA_15min.py", line 137, in on_bar
self.bg_15min.update_bar(bar)
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy/trader/utility.py", line 266, in update_bar
self.update_bar_minute_window(bar)
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy/trader/utility.py", line 306, in update_bar_minute_window
self.on_window_bar(self.window_bar)
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy_ctastrategy/strategies/MA_15min.py", line 144, in on_15min_bar
print(self.buy_price)
^^^^^^^^^^^^^^
AttributeError: 'MA_logtest' object has no attribute 'buy_price'

on_bar打印了一下，结果如下：
Traceback (most recent call last):
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy_ctastrategy/engine.py", line 619, in call_strategy_func
func()
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy_ctastrategy/strategies/MA_15min.py", line 108, in on_init
self.load_bar(
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy_ctastrategy/template.py", line 308, in load_bar
callback(bar)
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy_ctastrategy/strategies/MA_15min.py", line 138, in on_bar
print(self.buy_price)
^^^^^^^^^^^^^^

在on_tick环节打印是有正常数据的

你打印的是self.buy_price不是buy_price，但是策略类没有给self.buy_price这个全局变量定义

麻烦问下要怎么修改呢？在tick环节实例化之后，不能在bar中调用吗？
Traceback (most recent call last):
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy_ctastrategy/engine.py", line 619, in call_strategy_func
func()
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy_ctastrategy/strategies/MA_15min.py", line 109, in on_init
self.load_bar(
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy_ctastrategy/template.py", line 308, in load_bar
callback(bar)
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy_ctastrategy/strategies/MA_15min.py", line 139, in on_bar
self.bg_15min.update_bar(bar)
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy/trader/utility.py", line 266, in update_bar
self.update_bar_minute_window(bar)
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy/trader/utility.py", line 306, in update_bar_minute_window
self.on_window_bar(self.window_bar)
File "/opt/anaconda3/envs/VNT4/lib/python3.12/site-packages/vnpy_ctastrategy/strategies/MA_15min.py", line 187, in on_15min_bar
self.short(self.short_price, 1)
^^^^^^^^^^^^^^^^
AttributeError: 'MA_logtest' object has no attribute 'short_price'

你要局部创建就不要加self，要用全局变量就要在策略init函数定义呀