Concept: loops#

The for loop#

The for-loop repeats -simplified- a command n times:

Example#

The following loop is executed 5 times:

for i in range(5):
    print("I'm in a loop!")

The program gives the following output

I'm in a loop!
I'm in a loop!
I'm in a loop!
I'm in a loop!
I'm in a loop!

The counter variable#

You can use the variable i as a counter variable. It counts up (starting from 0):

Example#

for i in range(5):
    print(i)

The program gives the following output

0
1
2
3
4

General form:#

Generally written:

for i in range(max):
    <codeblock>

or

for i in range(min, max):
    <codeblock>

You can specify how many times the loop will be run or specify specific ranges:

Examples: Drawing with loops#

You can draw with loops:

from miniworldmaker import *

board = Board(200, 200)

for i in range(4):
    Circle((20 + 50 * i, 50), 20)
    
board.run()
circles

Checkerboard pattern#

With the module operator you can check if a result is divisible by 2, namely ``x divisible by 2 exactly if x % 2 == 0`

This can be used to draw chessboard-like patterns by combining loops with an if query:

from miniworldmaker import *

board = Board(200, 50)

for i in range(4):
    rect = Rectangle((50 * i, 0), 50, 50)
    if i % 2 == 0:
        rect.color = (255,0,0, 255)
    else:
        rect.color = (255, 255, 255, 255)
    
board.run()
checkers

Graphs#

Graphs can also be drawn in this way:

from miniworldmaker import *

board = Board(400, 400)


for x in range(400):
    gl = 0.5*x + 50
    y = 400 - gl
    Point((x, y))
    
board.run()
graphs

Nested loops#

You can use nested loops to draw multidimensional patterns.

from miniworldmaker import *

board = Board(200, 200)

for i in range(4):
    for j in range(4):
        Circle((20 + 50 * i, 20 + 50 * j), 20)
    
board.run()
nested loop