Christmas Tree in Python Turtle

Intermediate · Festivals · 111 lines · draws in about 15 seconds

This program draws a Christmas tree from three stacked triangles, then decorates it with ornaments from a list, a gold star and presents under a snowy sky.

Christmas Tree in Python Turtle: the finished drawing

import random

import turtle

random.seed(25)

screen = turtle.Screen()

screen.title("Christmas Tree")

screen.bgcolor("midnightblue")

t = turtle.Turtle()

def rectangle(x, y, width, height, color):

"""A filled rectangle with its bottom-left corner at (x, y)."""

t.penup()

t.goto(x, y)

t.setheading(0)

t.pendown()

t.color(color)

t.begin_fill()

for side in range(2):

t.forward(width)

t.left(90)

t.forward(height)

t.left(90)

t.end_fill()

def triangle(base_y, width, height, color):

"""One layer of the tree: a triangle standing on y = base_y."""

t.penup()

t.goto(-width / 2, base_y)

t.pendown()

t.color(color)

t.begin_fill()

t.goto(width / 2, base_y)

t.goto(0, base_y + height)

t.goto(-width / 2, base_y)

t.end_fill()

def present(x, y, size, box_color, ribbon_color):

"""A square present with a ribbon both ways and a bow on top."""

rectangle(x, y, size, size, box_color)

rectangle(x + size / 2 - 4, y, 8, size, ribbon_color)

rectangle(x, y + size / 2 - 4, size, 8, ribbon_color)

t.penup()

t.goto(x + size / 2 - 8, y + size + 6)

t.dot(16)

t.goto(x + size / 2 + 8, y + size + 6)

t.dot(16)

# Falling snow. Speed 0 puts every flake down at once, instead of

# making the turtle walk across the sky to each one.

t.speed(0)

t.penup()

for flake in range(60):

t.goto(random.randint(-300, 300), random.randint(-180, 215))

t.dot(random.randint(3, 7), "white")

# Snowy ground: a gentle hill made from a slice of a very big circle

t.speed(7)

t.goto(-285, -215)

t.setheading(15)

t.pendown()

t.color("white")

t.begin_fill()

t.circle(-1100, 30, steps=30)

t.goto(-285, -215)

t.end_fill()

# Trunk, then three layers of branches from the bottom up

rectangle(-22, -175, 44, 60, "saddlebrown")

triangle(-130, 300, 150, "#1d6b35")

triangle(-50, 240, 140, "#238a43")

triangle(30, 170, 130, "#2ea356")

# Ornaments in rows, taking the colours in turn

colors = ["red", "gold", "deepskyblue", "hotpink", "orange"]

ornaments = [

(-110, -112), (-55, -100), (0, -112), (55, -100), (110, -112),

(-85, -32), (-30, -20), (30, -32), (85, -20),

(-50, 48), (0, 60), (50, 48),

(-20, 115), (20, 115),

]

t.penup()

for number, (x, y) in enumerate(ornaments):

t.goto(x, y)

t.dot(18, colors[number % len(colors)])

# A gold star on top

t.goto(0, 185)

t.setheading(288)

t.pendown()

t.color("gold")

t.begin_fill()

for point in range(5):

t.forward(19)

t.left(72)

t.forward(19)

t.right(144)

t.end_fill()

# Presents under the tree

present(-170, -190, 70, "crimson", "gold")

present(95, -190, 60, "royalblue", "white")

present(-75, -200, 40, "darkorchid", "lightpink")

t.hideturtle()

turtle.done()

Open in the editor

How the code works

Layers of the tree

Each layer is a triangle standing on the line y = base_y, centred on x = 0. Three calls with narrower, higher triangles stack into a tree.

def triangle(base_y, width, height, color):
    """One layer of the tree: a triangle standing on y = base_y."""
    t.penup()
    t.goto(-width / 2, base_y)
    t.pendown()
    t.color(color)
    t.begin_fill()
    t.goto(width / 2, base_y)
    t.goto(0, base_y + height)
    t.goto(-width / 2, base_y)
    t.end_fill()

Presents from rectangles

A present is three rectangles: the box and two thin ribbon strips across the middle. Two dots on top make the bow.

def present(x, y, size, box_color, ribbon_color):
    """A square present with a ribbon both ways and a bow on top."""
    rectangle(x, y, size, size, box_color)
    rectangle(x + size / 2 - 4, y, 8, size, ribbon_color)
    rectangle(x, y + size / 2 - 4, size, 8, ribbon_color)
    t.penup()
    t.goto(x + size / 2 - 8, y + size + 6)
    t.dot(16)
    t.goto(x + size / 2 + 8, y + size + 6)
    t.dot(16)

Snow in random places

random.randint() picks a place and a size for each of 60 flakes. random.seed(25) at the top makes the same numbers come out on every run, so the picture never changes.

for flake in range(60):
    t.goto(random.randint(-300, 300), random.randint(-180, 215))
    t.dot(random.randint(3, 7), "white")

Ornaments that take turns

enumerate() numbers the ornaments 0, 1, 2 and so on, and number % len(colors) turns that number into a place in the colour list, so the colours repeat in order.

for number, (x, y) in enumerate(ornaments):
    t.goto(x, y)
    t.dot(18, colors[number % len(colors)])

Make it yours

Change the code above and press Run. Some ideas:

Add more ornaments by adding (x, y) pairs to the ornaments list, for example (0, 0).
Change range(60) to range(200) for a heavier snowfall.
Add a fourth present with present(30, -205, 45, "darkorange", "white") before t.hideturtle().

What it uses

functions with parameters
lists of tuples
random with a seed
enumerate and %

Every turtle command the site supports is listed on Python turtle online.