Simplify Python Turtle plotting of similar functions

Question

Is there a way to simplify this function, in terms of less if statements and typing the same code over and over?

This function creates sine graphs based on the number the user requests. There is a lot of repeating code. I tried to use lists to store the objects, but get an error when trying to access them. How can I fix this?

 def createWaves(amp, count):
            even_num = [2, 4, 6, 8, 10, 12]
            alpha = createTurtle("turtle", "darkcyan", 2)
            alpha.ht()
            beta = createTurtle("turtle", "purple", 2)
            beta.ht()
            gamma = createTurtle("turtle", "orange", 2)
            gamma.ht()
            delta = createTurtle("turtle", "magenta", 2)
            delta.ht()
            epsilon = createTurtle("turtle", "deepskyblue", 2)
            epsilon.ht()
            zeta = createTurtle("turtle", "green", 2)
            zeta.ht()
            omega = createTurtle("turtle", "black", 3)
            omega.ht()
            if count == 0:
                alpha.st()
                for x in range(361):
                    y_alpha = (amp/even_num[0]) *(math.sin(math.radians(x*even_num[0])))
                    alpha.goto(x, y_alpha)
            elif count == 1:
                alpha.st()
                beta.st()
                omega.st()
                for x in range(361):
                    y_alpha = (amp/even_num[0]) *(math.sin(math.radians(x*even_num[0])))
                    y_beta = (amp/even_num[1]) *(math.sin(math.radians(x*even_num[1])))
                    y_omega = y_alpha + y_beta
                    alpha.goto(x, y_alpha)
                    beta.goto(x, y_beta)
                    omega.goto(x, y_omega)
            elif count == 2:
                alpha.st()
                beta.st()
                gamma.st()
                omega.st()
                for x in range(361):
                    y_alpha = (amp/even_num[0]) *(math.sin(math.radians(x*even_num[0])))
                    y_beta = (amp/even_num[1]) *(math.sin(math.radians(x*even_num[1])))
                    y_gamma = (amp/even_num[2]) *(math.sin(math.radians(x*even_num[2])))
                    y_omega = y_alpha + y_beta + y_gamma
                    alpha.goto(x, y_alpha)
                    beta.goto(x, y_beta)
                    gamma.goto(x, y_gamma)
                    omega.goto(x, y_omega)

Answer 1

Here's a reimplementation that avoids the duplication and works for counts from 1 up, to the limit of EVEN_NUMBERS and COLORS :

import math
from turtle import Turtle, Screen

EVEN_NUMBERS = [2, 4, 6, 8, 10, 12]

COLORS = ["darkcyan", "purple", "orange", "magenta", "deepskyblue", "green", "black"]

def createWaves(amp, count):

    screen.tracer(False)

    for x in range(361):
        y_offsets = []

        for i in range(count):
            turtles[i].showturtle()

            y_offset = math.sin(math.radians(x * EVEN_NUMBERS[i])) * amp / EVEN_NUMBERS[i]

            turtles[i].goto(x, y_offset)

            y_offsets.append(y_offset)

        if count > 1:
                turtles[-1].showturtle()
                turtles[-1].goto(x, sum(y_offsets))

        screen.update()

    screen.tracer(True)

screen = Screen()

turtles = []

for color in COLORS:
    turtle = Turtle("turtle", visible=False)
    turtle.speed('fastest')
    turtle.color(color)
    turtle.width(2)

    turtles.append(turtle)

turtles[-1].width(3)  # summation turtle

createWaves(100, 4)

screen.exitonclick()