问题描述
我经常遇到一个关于 futures[x].result() 的关键错误，我不确定我做错了什么
也许我没有正确使用等待？
from concurrent.futures import wait,ALL_COMPLETED
import concurrent.futures
import datetime
from datetime import timedelta
import yfinance as yf
import pandas as pd
pool = concurrent.futures.ThreadPoolExecutor(8)
end = datetime.date.today()
start = end - timedelta(weeks=104)
stocks = ['GOOG','CSCO']
def dl(stock):
return yf.download(stock,start=start,end=end).iloc[:,:5].dropna(axis=0,how='any')
futures = [pool.submit(dl,args) for args in stocks]
wait(futures,return_when=ALL_COMPLETED)
stocks_data = pd.DataFrame()
for x in range(0,len(stocks)):
prices = pd.DataFrame(futures[x].result())
prices['Symbol'] = stocks[x]
stocks_data = pd.concat([stocks_data,prices])
print(stocks_data)
这是我得到的（堆栈）错误
除了这个错误，我真的没有更多的细节要添加，但它要求我指定额外的注释，所以我在这里填充空间以便我可以提供堆栈跟踪
KeyError Traceback (most recent call last)
<ipython-input-160-3da302790b49> in <module>
24 stocks_data = pd.DataFrame()
25 for x in range(0,len(stocks)):
---> 26 prices = pd.DataFrame(futures[x].result())
27 prices['Symbol'] = stocks[x]
28 stocks_data = pd.concat([stocks_data,prices])
/usr/lib/python3.6/concurrent/futures/_base.py in result(self,timeout)
423 raise CancelledError()
424 elif self._state == FINISHED:
--> 425 return self.__get_result()
426
427 self._condition.wait(timeout)
/usr/lib/python3.6/concurrent/futures/_base.py in __get_result(self)
382 def __get_result(self):
383 if self._exception:
--> 384 raise self._exception
385 else:
386 return self._result
/usr/lib/python3.6/concurrent/futures/thread.py in run(self)
54
55 try:
---> 56 result = self.fn(*self.args,**self.kwargs)
57 except BaseException as exc:
58 self.future.set_exception(exc)
<ipython-input-160-3da302790b49> in dl(stock)
16
17 def dl(stock):
---> 18 return yf.download(stock,how='any')
19
20
/usr/local/lib/python3.6/dist-packages/yfinance/multi.py in download(tickers,start,end,actions,threads,group_by,auto_adjust,back_adjust,progress,period,interval,prepost,proxy,rounding,**kwargs)
117
118 if len(tickers) == 1:
--> 119 return shared._DFS[tickers[0]]
120
121 try:
KeyError: 'CSCO'
解决方法
看起来线程很糟糕（我读到我应该在某处使用进程而不是线程）
from concurrent.futures import wait,ALL_COMPLETED
import concurrent.futures
import datetime
from datetime import timedelta
import yfinance as yf
import pandas as pd
#pool = concurrent.futures.ThreadPoolExecutor(8)
pool = concurrent.futures.ProcessPoolExecutor()
end = datetime.date.today()
start = end - timedelta(weeks=104)
stocks = ['GOOG','CSCO']
def dl(stock):
return yf.download(stock,start=start,end=end).iloc[:,:5].dropna(axis=0,how='any')
futures = [pool.submit(dl,args) for args in stocks]
wait(futures,timeout=None,return_when=ALL_COMPLETED)
stocks_data = pd.DataFrame()
for x in range(0,len(stocks)):
prices = pd.DataFrame(futures[x].result())
prices['Symbol'] = stocks[x]
stocks_data = pd.concat([stocks_data,prices])
print(stocks_data)