quick start optimization example output problem

[asuralm]

This is a bizarre problem. I copy and paste the last example i.e. the optimization one in the QuickStart page!
https://www.backtrader.com/docu/quickstart/quickstart.html

I made a small modification to the datafeed but the rest are exactly the same.
If I use Visual Studio to run the code, I have got the same console output as shown in the webpage.

But if I use IDLE, my python version is 3.5.2, the code gives me the result something like

There is no output at all. If I write a print function in the name='main', it will print normally.

However, if I don't use the optstrategy but use addstrategy(TestStrategy), the output works find and I can get output.

It seems that the optstrategy hides the print output somehow.

Any help please?
Thanks

[backtrader]

It may be the same root cause as spyder and other shells which take over the initialization and prevent multiprocessing from working. Some references:

• https://github.com/mementum/backtrader/issues/118
• https://github.com/mementum/backtrader/issues/133
• http://stackoverflow.com/questions/38884587/multithreading-frozen-in-python-spyder-but-not-command-prompt-windows-10