variables

Defining Variables

We have already used variables in the previous examples.

You can define new variables by writing:

self.variable name = value
  • The self always refers to the current object. For example, if you have created several circles, self means that the variable name to this circle and to no other.

  • A variable is a Name for an object. An object can be a number, a word, a geometric shape or much more. By giving the object a name, you can access it and change it.

Consider the following example:

from miniworldmaker import *


class MyBoard(ProcessingBoard):

    def on_setup(self):
        self.circle1 = Circle((40, 40), 60, 0, color = (255, 0, 0, 100))
        self.circle2 = Circle((80, 100), 60, 0, color = (0, 255, 0, 100))

    def on_mouse_left(self, mouse_pos):
        self.circle1.x = 150

my_board = MyBoard(400, 400)
my_board.show()

A board of the type MyBoard has two circles. By giving the circles names. (namely self.circle1 and self.circle2) you can also access the circles elsewhere.

Here the x-coordinate of the first circle is set to 150.

../_images/movement.gif

The Random Function

The Random function allows you to assign random values to things. First you have to randomly import the library at the beginning of your file:

import random

Then a single command is sufficient for the first one.

random.randint(0, 5)

This creates a random number between 0 and 5

The following program lets a circle jump to a random position:

from miniworldmaker import *
import random


class MyBoard(ProcessingBoard):

    def on_setup(self):
        self.circle1 = Circle((40, 40), 60, 0, color=(255, 0, 0, 255)))

    def on_mouse_left(self, mouse_pos):
        self.circle1.x = random.randint(0, 260)
        self.circle1.y = random.randint(0, 200)


my_board = MyBoard(260, 200)
my_board.show()