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

1. Counting Loop 2 Loop1.py

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

Using the Counting Loop Var. 4 Loop3.py

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

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

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

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.

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.

Square.py with a Loop 10

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

Shape.py 12

 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

Revised Shape.py 14

 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

ShapeInput.py 16

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A Square Spiral 18 SquareSpiral1.py

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

Square  Circle 20

Square Spiral Again 21 ColorSquareSpiral.py with different colors

Spiral with Adjustable Sides 22 ColorSpiral.py

Execution: 6  2 sides 23

Spiral Steps 24 Spiral Steps.py

Execution 25

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

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

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

While that Likes "3" 29 While3.py

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

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

4. A Number Guessing Game 32 GuessingGame.py

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35 Uses two modules; a while loop; if tests

5. Ghost Game

ghostGame.py 37

6. Hangman 38 hangman.py