Analog Clock in Python Turtle

Intermediate · Things to draw · 76 lines · draws in about 10 seconds

Clock angles go clockwise from 12 while turtle headings go anticlockwise from 3, so setheading(90 - angle) turns any clock angle into a turtle heading.

Analog Clock in Python Turtle: the finished drawing

import turtle

screen = turtle.Screen()

screen.bgcolor("lightsteelblue")

screen.title("Clock")

t = turtle.Turtle()

t.speed(10)

def disc(radius, color):

# A filled circle centred on (0, 0)

t.penup()

t.goto(0, -radius)

t.setheading(0)

t.color(color)

t.begin_fill()

t.circle(radius, steps=90)

t.end_fill()

def face_the(angle):

# Stand in the middle and face a clock angle: 0 is 12 o'clock,

# and clock angles go clockwise while turtle headings go anticlockwise

t.penup()

t.goto(0, 0)

t.setheading(90 - angle)

# The frame and the white face

disc(215, "darkslategray")

disc(195, "ivory")

# 60 marks round the edge: a long thick one every 5 minutes

t.pencolor("darkslategray")

for minute in range(60):

face_the(minute * 6)

if minute % 5 == 0:

t.pensize(6)

t.forward(162)

t.pendown()

t.forward(22)

else:

t.pensize(2)

t.forward(176)

t.pendown()

t.forward(8)

# The numbers 1 to 12, one every 30 degrees

for number in range(1, 13):

face_the(number * 30)

t.forward(135)

# write() puts text above the turtle, so step down half its height

t.sety(t.ycor() - 17)

t.write(number, align="center", font=("Arial", 26, "bold"))

# The hands at 10:10

hours = 10

minutes = 10

t.pencolor("black")

face_the(hours * 30 + minutes * 0.5)

t.pendown()

t.pensize(12)

t.forward(80)

face_the(minutes * 6)

t.pendown()

t.pensize(7)

t.forward(112)

# A red cap in the middle where the hands meet

t.penup()

t.goto(0, 0)

t.dot(26, "crimson")

t.hideturtle()

turtle.done()

Open in the editor

How the code works

Facing a clock angle

Every mark, number and hand starts in the middle of the clock. face_the(0) points the turtle at the 12, face_the(90) at the 3, and so on, because setheading(90 - angle) converts clock angles to turtle headings.

def face_the(angle):
    # Stand in the middle and face a clock angle: 0 is 12 o'clock,
    # and clock angles go clockwise while turtle headings go anticlockwise
    t.penup()
    t.goto(0, 0)
    t.setheading(90 - angle)

Minute marks

One mark every 6 degrees makes 60 marks. minute % 5 == 0 is true at 0, 5, 10 and so on, and those marks are thicker and longer. The turtle moves out with the pen up and draws only the last few steps.

# 60 marks round the edge: a long thick one every 5 minutes
t.pencolor("darkslategray")
for minute in range(60):
    face_the(minute * 6)
    if minute % 5 == 0:
        t.pensize(6)
        t.forward(162)
        t.pendown()
        t.forward(22)
    else:
        t.pensize(2)
        t.forward(176)
        t.pendown()
        t.forward(8)

Numbers

Each number is 30 degrees further round and 135 steps from the middle. write() puts text above the turtle, so it steps down 17 first, and align="center" centres the text from left to right.

# The numbers 1 to 12, one every 30 degrees
for number in range(1, 13):
    face_the(number * 30)
    t.forward(135)
    # write() puts text above the turtle, so step down half its height
    t.sety(t.ycor() - 17)
    t.write(number, align="center", font=("Arial", 26, "bold"))

Hands at 10:10

The minute hand moves 6 degrees per minute. The hour hand moves 30 degrees per hour plus half a degree per minute, so at 10:10 it sits a little past the 10.

# The hands at 10:10
hours = 10
minutes = 10
t.pencolor("black")
face_the(hours * 30 + minutes * 0.5)
t.pendown()
t.pensize(12)
t.forward(80)
face_the(minutes * 6)
t.pendown()
t.pensize(7)
t.forward(112)

Make it yours

Change the code above and press Run. Some ideas:

Show another time: change hours = 10 and minutes = 10 to 3 and 45.
Change disc(215, "darkslategray") to disc(215, "goldenrod") for a brass frame.
Add a second hand after the minute hand: face_the(180), t.pendown(), t.pensize(2), t.pencolor("crimson") and t.forward(150).

What it uses

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