This is just a short part of my code (I'm new with python). The goal is to move all of the elements one position forward.

from turtle import  Turtle

turtles = []

for i in range(4):
    t = Turtle()
    t.color("white")
    t.setx(i*-20)
    turtles.append(t)

for i in range(len(turtles)-1, 0, -1):
    print(f"Element in position {i} with xcor {turtles[i].xcor()} will have the xcor {turtles[i-1].xcor()}")
    turtles[i] = turtles[i-1]

turtles[0].forward(20)
print(" After modification of element in position 0")
print(f"Element in position 0 has xcor = {turtles[0].xcor()}")
print(f"Element in position 1 has xcor = {turtles[1].xcor()}")

However, I do not understand why the objects in positions 0 and 1 were modified at the same time.

Element in position 3 with xcor -60 will have the xcor -40
Element in position 2 with xcor -40 will have the xcor -20
Element in position 1 with xcor -20 will have the xcor 0
 After modification of element in position 0
Element in position 0 has xcor = 20.0
Element in position 1 has xcor = 20.0

I was waiting to see the xcor = 0 for element in position 1.

CodePudding user response：

turtles[1] and turtles[0] are the same object. In other words, turtles[1] is turtles[0].

To copy a Turtle, use .clone(), for example, here:

turtles[i] = turtles[i-1].clone()