我有一个策略，包括使用多个技术指标来生成买入信号。
我将如何使用 Pyalgotrade 为多个代码列表实现这一点，这样策略不是基于每个代码进行分析，而是基于所有列表中所有交易的结果？
请在下面找到说明程序各个部分的代码（示例）：
from pyalgotrade import strategy
from pyalgotrade.barfeed import yahoofeed
from pyalgotrade.technical import ma
class MyStrategy(strategy.BacktestingStrategy):
def __init__(self, feed, instrument, smaPeriod):
super(MyStrategy, self).__init__(feed, 1000)
self.__position = None
self.__instrument = instrument
# We'll use adjusted close values instead of regular close values.
self.setUseAdjustedValues(True)
self.__sma = ma.SMA(feed[instrument].getPriceDataSeries(), smaPeriod)
def onEnterOk(self, position):
execInfo = position.getEntryOrder().getExecutionInfo()
self.info("BUY at $%.2f" % (execInfo.getPrice()))
def onEnterCanceled(self, position):
self.__position = None
def onExitOk(self, position):
execInfo = position.getExitOrder().getExecutionInfo()
self.info("SELL at $%.2f" % (execInfo.getPrice()))
self.__position = None
def onExitCanceled(self, position):
# If the exit was canceled, re-submit it.
self.__position.exitMarket()
def onBars(self, bars):
# Wait for enough bars to be available to calculate a SMA.
if self.__sma[-1] is None:
return
bar = bars[self.__instrument]
# If a position was not opened, check if we should enter a long position.
if self.__position is None:
if bar.getPrice() > self.__sma[-1]:
# Enter a buy market order for 10 shares. The order is good till canceled.
self.__position = self.enterLong(self.__instrument, 10, True)
# Check if we have to exit the position.
elif bar.getPrice() < self.__sma[-1] and not self.__position.exitActive():
self.__position.exitMarket()
def run_strategy(smaPeriod):
# Load the yahoo feed from the CSV file
feed = yahoofeed.Feed()
feed.addBarsFromCSV("orcl", "orcl-2000.csv")
# Evaluate the strategy with the feed.
myStrategy = MyStrategy(feed, "orcl", smaPeriod)
myStrategy.run()
print "Final portfolio value: $%.2f" % myStrategy.getBroker().getEquity()
run_strategy(15)