I am not at this point interested in an efficient way of producing

concentric circles: I want to see what I have to do to get this way to

work

為了解決OP的問題，對其原始代碼進行更改以使其正常工作是很簡單的：turtle_pos(trl, [trl.xcor() + mv, trl.ycor() - mv], 1)

trl.circle(j * radius)

變成：turtle_pos(trl, [trl.xcor(), trl.ycor() - mv], 1)

trl.circle(j * mv + radius)

包含上述修復和一些樣式更改的完整代碼：import turtle

def turtle_pos(art, posxy, lift):

if lift:

art.penup()

art.setposition(posxy)

art.pendown()

def drawit(tshape, tcolor, pen_color, pen_thick, scolor, radius, mv):

window = turtle.Screen() # Request a screen

window.bgcolor(scolor) # Set its color

#...code that defines the turtle trl

trl = turtle.Turtle(tshape)

trl.pencolor(pen_color)

trl.fillcolor(tcolor) # not filling but makes body of turtle this color

trl.width(pen_thick)

for j in range(10):

turtle_pos(trl, (trl.xcor(), trl.ycor() - mv), True)

trl.circle(j * mv + radius)

window.mainloop()

drawit("turtle", "purple", "green", 4, "black", 20, 30)