I wrote a python module designed to solve the Tetris cube tiling puzzle, and there is a lot of code inside it, But when I press F5 to run the program, the shell starts again, but then it stops working, even when I do not enable debugging anything, even when it does not want to run. I have placed a print statement at the very beginning of the program, even then it has not been executed, and I can not terminate the program using ctrl-c. I was able to fix this problem by putting some functions defined in a separate module, and now it works fine, but if I create a new function, and add enough print statements, then the problem looks again, but It can be fixed just by removing a statement that i use Python 2.7.8