https://www.quantopian.com/ https://www.quantopian.com/ has a great community, lots of examples & tuts available, and you can look at everyone else's algos. It'

https://www.quantopian.com/ https://www.quantopian.com/ has a great community, lots of examples & tuts available, and you can look at everyone else's algos. It's free, there's free backtesting, etc. They're a "crowdsourced hedge fund" using Python and the zipline library.