17.7. Objects as Arguments and Parameters¶
You can pass an object as an argument in the usual way. We’ve already seen
this in some of the turtle examples where we passed the turtle to
some function like
drawRectangle so that the function could
control and use whatever turtle instance we passed to it.
Here is a simple function called
distance involving our new
Point objects. The job of this function is to figure out the
distance between two points.
distance takes two points and returns the distance between them. Note that
distance is not a method of the Point class. You can see this by looking at the indentation pattern. It is not inside the class definition. The other way we
can know that
distance is not a method of Point is that
self is not included as a formal parameter. In addition, we do not invoke
distance using the dot notation.