I tried to refactor the code of Python beginner (junior high school student)

A Python program written by a junior high school student. It was well done for the first time. At first, you can use any writing style. I think.

However, in order to be able to create difficult programs, it is important to organize your mind and make the program easy to understand. I rewrote this program as an example.

Original program

I was able to draw beautiful figures. It is wonderful to devise a way to put out colorful shades. I made it by carefully considering the conditional division of the if statement and the calculation formula.

number = int(input("How many circles do you draw?"))
R = 1.0
G = 0.0
B = 0.0
color = 0
from turtle import *
delay(5)
shape("turtle")
for i in range(number):
    color = int(360/number*i)
    if color <= 60:
        R = 1.0
        G = color/60
        B = 0.0
    elif color <= 120:
        R = 2.0-color/60
        G = 1.0
        B = 0.0
    elif color <= 180:
        R = 0.0
        G = 1.0
        B = color/60-2.0
    elif color <= 240:
        R = 0.0
        G = 4.0-color/60
        B = 1.0
    elif color <= 300:
        R = color/60-4.0
        G = 0.0
        B = 1.0
    elif color <= 360:
        R = 1.0
        G = 0.0
        B = 6.0-color/60

    pencolor(R,G,B)
    circle(100)
    left(360/number)
done()

Execution result

Start cooking

import moves first The part for finding the RGB value is functionalized I can't see the regularity of the formula in the if statement. I think it was made by trial and error. Changed to a regular expression with the same result. = Is included in the conditional expression of the if statement, but the result does not change even if = is excluded. color Considering that the range is 0 to 359, it seems more appropriate to not add =.

import turtle

def color2rgb(color):
    if color < 60:
        R = 1.0
        G = color/60
        B = 0.0
    elif color < 120:
        R = 1.0-(color-60)/60
        G = 1.0
        B = 0.0
    elif color < 180:
        R = 0.0
        G = 1.0
        B = (color-120)/60
    elif color < 240:
        R = 0.0
        G = 1.0-(color-180)/60
        B = 1.0
    elif color < 300:
        R = (color-240)/60
        G = 0.0
        B = 1.0
    elif color < 360:
        R = 1.0
        G = 0.0
        B = 1.0-(color-300)/60
    return(R, G, B)

def draw(number):
    turtle.delay(5)
    turtle.shape("turtle")
    for i in range(number):
        color = int(360 / number * i)
        turtle.pencolor(color2rgb(color))
        turtle.circle(100)
        turtle.left(360 / number)
    turtle.done()

number = int(input("How many circles do you draw?"))
draw(number)

further

If you look closely at color2rgb (), the values of R, G, and B have the same shape with a phase shift of 120. You can also stop the if statement and create a table. However, if you make it into a table, the readability will decrease a little. Let's do this.

import turtle

def color2r(color):
    color = color % 360
    if color < 60:
        R = 1.0
    elif color < 120:
        R = 1.0-(color-60)/60
    elif color < 180:
        R = 0.0
    elif color < 240:
        R = 0.0
    elif color < 300:
        R = (color-240)/60
    elif color < 360:
        R = 1.0
    return R

def color2rgb(color):
    return color2r(color), color2r(color-120), color2r(color-240)

def draw(number):
    turtle.delay(5)
    turtle.shape("turtle")
    for i in range(number):
        color = int(360 / number * i)
        turtle.pencolor(color2rgb(color))
        turtle.circle(100)
        turtle.left(360 / number)
    turtle.done()

number = int(input("How many circles do you draw?"))
draw(number)

Extra edition

Looking at the comments I received, the image swelled, so I made a function table version. I don't know if it's easy to read, but I like it.

import turtle

convert_func_table = [lambda x: 1.0, lambda x:1.0-x/60, lambda x:0, lambda x:0, lambda x:x/60, lambda x:1.0]

def convert(i,fine):
    return convert_func_table[i%6](fine)

def color2rgb(color):
    i, fine = divmod(color, 60)
    return (
        convert(i, fine),
        convert(i+4, fine),
        convert(i+2, fine),
    )

def draw(number):
    turtle.delay(5)
    turtle.shape("turtle")
    for i in range(number):
        color = int(360/number*i)
        turtle.pencolor(color2rgb(color))
        turtle.circle(100)
        turtle.left(360/number)
    turtle.done()

number = int(input("How many circles do you draw?"))
draw(number)

Thank you, Mr. K, for providing the program.