Pyalgotrade Tutorial Attribute Error

Question

I have been googling for a while now, but am still unable to find a solution, or even determine the problem, honestly.

My installation of Python and Pyalgotrade is correct, as verified by the successful imports.

Nonetheless, I can't manage to run the example code in the tutorial, it always throws:

AttributeError: MyStrategy instance has no attribute 'info'

Here's the example code:

from pyalgotrade import strategy
from pyalgotrade.barfeed import yahoofeed


class MyStrategy(strategy.BacktestingStrategy):
    def __init__(self, feed, instrument):
        strategy.BacktestingStrategy.__init__(self, feed)
        self.__instrument = instrument

    def onBars(self, bars):
        bar = bars[self.__instrument]
        self.info(bar.getClose())

# Load the yahoo feed from the CSV file
feed = yahoofeed.Feed()
feed.addBarsFromCSV("orcl", "orcl-2000.csv")

# Evaluate the strategy with the feed's bars.
myStrategy = MyStrategy(feed, "orcl")
myStrategy.run()

And the iPython Notebook output:

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-1-f786d1b471f7> in <module>()
 18 # Evaluate the strategy with the feed's bars.
 19 myStrategy = MyStrategy(feed, "orcl")
---> 20 myStrategy.run()

/usr/local/lib/python2.7/site-packages/pyalgotrade/strategy/__init__.pyc in run(self)
398                 self.onStart()
399 
--> 400                 self.__dispatcher.run()
401 
402                 if self.__feed.getCurrentBars() != None:

/usr/local/lib/python2.7/site-packages/pyalgotrade/observer.pyc in run(self)
139                                 subject.start()
140 
--> 141                         while not self.__stopped and self.__dispatch():
142                                 pass
143                 finally:

/usr/local/lib/python2.7/site-packages/pyalgotrade/observer.pyc in __dispatch(self)
131                                         nextDateTime = subject.peekDateTime()
132                                         if nextDateTime == None or nextDateTime ==   smallestDateTime:
--> 133                                                 subject.dispatch()
134                 return ret
135 

/usr/local/lib/python2.7/site-packages/pyalgotrade/feed/__init__.pyc in dispatch(self)
 95                 dateTime, values = self.getNextValuesAndUpdateDS()
 96                 if dateTime != None:
---> 97                         self.__event.emit(dateTime, values)
 98 
 99         def getKeys(self):

/usr/local/lib/python2.7/site-packages/pyalgotrade/observer.pyc in emit(self, *parameters)
 51                 self.__emitting = True
 52                 for handler in self.__handlers:
---> 53                         handler(*parameters)
 54                 self.__emitting = False
 55                 self.__applyChanges()

/usr/local/lib/python2.7/site-packages/pyalgotrade/strategy/__init__.pyc in __onBars(self, dateTime, bars)
386 
387                 # 1: Let the strategy process current bars and place orders.
--> 388                 self.onBars(bars)
389 
390                 # 2: Place the necessary orders for positions marked to exit on session close.

<ipython-input-1-f786d1b471f7> in onBars(self, bars)
 10     def onBars(self, bars):
 11         bar = bars[self.__instrument]
---> 12         self.info(bar.getClose())
 13 
 14 # Load the yahoo feed from the CSV file

AttributeError: MyStrategy instance has no attribute 'info'

Has anyone at least a hint on what the problem could be?

Answer 1

Which version of PyAlgoTrade are you using ?

import pyalgotrade
print pyalgotrade.__version__

Answer 2

Copied from question:

So, I updated PyAlgoTrade to 0.15, and now the sample code works. I did not investigate the cause of the error yet, but can safely say that 0.15 works as expected.