I managed to test different parameters of a strategy (eg. different moving-average window lengths) on a fixed datafeed. However, I failed so far to test a fixed set of parameters on different datafeeds.
For example (simplified), I would like to test a simple moving average crossover strategy with a window length of 7 days for three different stocks such as Apple, Google, Facebook, etc and see where it performs best.
I created a list with the different tickers, and then use
asset = random.sample(tickerlist,1)
Then for import something like:
data = bt.feeds.PandasData(dataname=asset)
This way I get a ticker out of my list. I then set all the optimization parameters that could affect data pre-loading to false:
cerebro = bt.Cerebro(stdstats=False, optreturn=False, runonce=False, preload=False, optdatas=False, maxcpus=1)
However, it seems that the "random.sample" is not re-executed at each run, as it always re-loads the same datafeed.
Any idea on how I could solve this would be highly appreciated!