1. 5. Loops 1 Let’s Learn Saenthong School, January – February 2016 Teacher: Aj. Andrew Davison, CoE, PSU Hat Yai Campus E-mail: ad@fivedots.coe.psu.ac.th Make a program do things over-and-over-and over again. Counting loops; Conditional loops. Games: guessing, ghost, hangman.

2. 1. Counting Loop 2 Loop1.py

3. Using the Counting Loop Variable 3 Loop2.py The [ … ] is called a list. More later

4. Using the Counting Loop Var. 4 Loop3.py

5. Counting without Numbers 5 A list can contain anything, not just numbers Coolest.py

6. Counting Loop Using a Range 6 Loop4.py Less typing, but it goes from 1 to 4

7. Eight Times Table 7 This range goes from 1 to 10 EightTimes.py

8. Range with a Step Amount 8 This range goes from 10 to 1 in a step of -1 BlastOff.py This program took 10 secs to run.

9. from turtle import Turtle t = Turtle() t.forward(100) t.right(90) t.forward(100) t.right(90) t.forward(100) t.right(90) t.forward(100) t.right(90) 2. Drawing a Turtle Square 9 This is Square.py from the Modules slides. The forward() and right() code is repeated four times. A loop will make this code smaller, and easier to change.

10. Square.py with a Loop 10

11. Square1.py with Variables 11 The variables make it easy to change the code. What if numSides == 3 and angle = 120?

12. Shape.py 12

13.  For a square, numSides == 4, angle == 90  For a triangle, numSides == 3, angle == 120  The math connection:  numSides * angle == 360  Test it. A 5-sided shape (pentagon) means:  5 * angle == 360  so angle = 360/5 Connect No. Sides and Angle 13

14. Revised Shape.py 14

15.  In ShapeInput.py  read in the numSides data using the turtle command numinput()  calculate the angle using the numSides data Make Shape Code Easier to Use 15

16. ShapeInput.py 16

17. 17

18. A Square Spiral 18 SquareSpiral1.py

19. Square (90   91  ) + Color 19 SquareSpiral3.py

20. Square  Circle 20

21. Square Spiral Again 21 ColorSquareSpiral.py with different colors

22. Spiral with Adjustable Sides 22 ColorSpiral.py

23. Execution: 6  2 sides 23

24. Spiral Steps 24 Spiral Steps.py

25. Execution 25

26.  A conditional loop uses a test to decide when to stop looping  the same kind of test as in "if" 3. Conditional Loops 26

27. Eight Times Table Again 27 i < 11 is the test the while body is run over and over most while body's need to include an increment WhileLess.py

28. Eight Times Table Problem 28 WhileProb.py i never changes because there is no increment. This means i never reaches 11 and so the loop never ends. I typed ctrl-c

29. While that Likes "3" 29 While3.py

30. Using continue in a Loop 30 Continuer.py continue makes Python start the next loop straight away

31. Using break in a Loop 31 Breaker.py break makes Python leave the loop

32. 4. A Number Guessing Game 32 GuessingGame.py

34. 34

35. 35 Uses two modules; a while loop; if tests

36. 5. Ghost Game 36 1 2 3

37. ghostGame.py 37

38. 6. Hangman 38 hangman.py