Homework for Week 4

Exercises

Modulo Practice

Modulo tells you the remainder from a division. The best way to think about this is to think about how many units are left until the next multiple.

For example, imagine you have a chicken that lays eggs. You have a computerized chicken hutch, so you know her total count of eggs. You want to only go in and get eggs when she has laid 12 of them. But you’ve had the chicken for so long, the total count is really high. One way of knowing how many are left until 12 is using modulo. Using modulo like this: total_count % 12 will be 0 when the total_count is a multiple of 12.

So, whatever modulo we are doing (12 in the egg example) lets us count to that number over and over!

Another example is music. If you want to count the beats in 4s and you know the total beats so far, you could just do modulo to find out which beat you are on, like this: beats % 4.

Finally, the last example of using modulo is with the chinese horoscope! With the horoscope, there are 12 animals. Each year is assigned an animal and every 12 years, the sequence of animals starts over!

Your task

Write your own horoscope. It would be twelve animals or it could be three. Using input, ask the user how old they are (remember to convert the input to an integer or float!).

Depending on their age, use modulo to find their horoscope! You should use if and elif statements. Remember that if you modulo by 3, then the result can only be 0, 1, or 2. If you modulo by 5, the result can only be 0, 1, 2, 3, or 4.

bonus

You could store horoscope messages in a list:

fruit_horoscopes = list()

banana_horoscope = "You are a banana!"
fruit_horoscopes.append(banana_horoscope)

apple_horoscope = "You are an apple!"
fruit_horoscopes.append(apple_horoscope)

And then you can use the modulo result to index into the list! This replaces the if statements.

Extra Things

Gifs with Turtles

Using the gifs with turtles requires that you have a gif file in the same folder as your python file. If you started a project in pycharm, it should have made you select a folder, and therefore you know where your python file is at.

One way to find good gifs is use to google’s advanced image search.

• There is a “file type” option. Use it to select gif.
• I would recommend also selecting “icon” under “image size” as well. Then, search for whatever you want!

I searched for robots and I found the one below. Note that for animated gifs, the animation won’t be shown! Only the first frame.

Once a gif file is in the same folder as your file, you can then do:

import turtle
turtle.register_shape('robot.gif')

bob = turtle.Turtle()
bob.shape('robot.gif')

turtle.done()

For fun, you could make the pen go up and just stamp:

bob.penup()
for i in range(4):
    bob.stamp()
    bob.forward(200)
    bob.left(90)

This leads to fun things like these: