Blocks with '>>>' are here to demostrate an interactive session (when the responses are important), like:  ```pycon  >>> 1.2 - 1.0  0.19999999999999996  ```    The ones with no '>>>' are to demonstrate code (implementation of classes, functions, ...) when there is typically no result, like:    ```  def foo(x, y):      return 5 * x - 3 * y  ```