Concept: loops
Contents
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()
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()
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()
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()
