Figuring out what dependencies are needed

Robert Kern robert.kern at
Wed Dec 11 14:38:24 CET 2013

On 2013-12-11 13:27, Steven D'Aprano wrote:
> On Wed, 11 Dec 2013 04:44:53 -0800, sal wrote:
>> Now I'd like to use the backtesting package from zipline (,
> ".io" is not normally a file extension for Python files. Are you sure
> that's Python code?

That's a package name, not a filename.

>> but while running the test script in iPython, I receive the following
>> error:
>> AssertionError                            Traceback (most recent call
>> last)
>> <ipython-input-6-f921351f78e2> in <module>()
>> ----> 1 data = load_from_yahoo()
>>        2 dma = DualMovingAverage()
>>        3 results =
> I think you may be missing one or more lines? Perhaps something like
> "AssertionError: blah blah blah" appearing after that?
> For those unfamiliar with iPython, rather than a standard Traceback, that
> appears to suggest that is raising AssertionError, but we
> can't see what (if any) error message is given by that assert, or how it
> fails.

No, the ----> arrow points to the active line in that frame of the traceback. 
Unfortunately, the OP cut off the remaining frames under `load_from_yahoo()` 
actually has the assert that is failing.

Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco

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