Recursive generator in Python 3.5

[tpqnnd01 at gmail.com]

Hi ChrisA,

Thank you so much for sharing this point, I just concern to the point that: normally, I found that the generator (it may be recursive generator also) do not apply the "return" keyword, just the yield only. But when I delete one or both of "return" keyword above, the code do not action. What is the concern here, could you share more experience on that,