60 Chapter 4

360 degrees by that number, and we’ll find the number of degrees

to turn left each pass through the loop. Type and run the following

code as RosetteGoneWild.py:

RosetteGoneWild.py

import turtle
t = turtle.Pen()

Ask the user for the number of circles in their rosette, default to 6

u number_of_circles = int(turtle.numinput("Number of circles",
"How many circles in your rosette?", 6))
v for x in range(number_of_circles):
w t.circle(100)
x t.left(360/number_of_circles)

At u, we assign a variable called number_of_circles using a

couple of functions together. We’re using Turtle’s numinput() func-

tion to ask the user how many circles to draw. The first value,

Number of circles, is the pop-up window’s title; the second, How many

circles in your rosette?, is the text that will appear in the box;

and the last, 6 , is a default value in case the user doesn’t enter

anything. The int() function outside numinput() turns the user’s

number into an integer we can use

in our range() function. We store the

user’s number as number_of_circles to

use as the size of the range() in our

drawing loop.

The for statement at v is our loop.

It uses the number_of_circles variable to

loop x through a list of that many num-

bers. The command to draw a circle

is still the same at w and will draw

circles with a radius of 100 pixels.

At x, we’re dividing a full turn of

360 degrees by the number of circles so

we can draw the circles evenly spaced

around the center of the screen. For

example, if the user enters 30 as the

number of circles, 360 ÷ 30 would give

us a 12-degree turn between each of

the 30 circles around our center point,

as shown in Figure 4-3.