digital clock using python

September 03, 2025

7-Segment Digital Clock using Python Tkinter

Digital clocks are an interesting way to practice Python GUI programming. In this project, we build a 7-segment digital clock using Python Tkinter. Instead of showing plain text time, this clock uses a 7-segment style display, similar to the ones seen in digital watches, calculators, and old LED clocks.

Why Build a 7-Segment Clock in Python?

Most Python clocks simply display time using labels, but this project is unique because it mimics the classic 7-segment LED design. This helps beginners understand:

  • How to draw custom shapes (segments) in Tkinter Canvas.
  • How to map digits into 7-segment format.
  • How to update time dynamically using after().

Key Features of the Project

  • 7-Segment Digits: Each number is drawn with 7 polygons, simulating LED segments.
  • Digital Clock Functionality: Shows the current system time in 12-hour format with AM/PM.
  • Colon & AM/PM Display: Adds colon dots and AM/PM letters for a realistic clock.
  • Real-Time Update: Refreshes every second using Tkinter’s after() function.
  • Stylish Design: Black background with glowing red digits for a retro digital effect.

🌐 Digital Clock 



import tkinter as tk
from time import strftime

root = tk.Tk()
root.title("7-Segment Digital Clock")
root.configure(bg="black")

# Window size 
root.geometry("300x200")
root.resizable(False, False)

canvas = tk.Canvas(root, bg="black", width=300, height=200, highlightthickness=0)
canvas.pack()

# Segment map
digit_segments = {
    "0": [1,1,1,1,1,1,0],
    "1": [0,1,1,0,0,0,0],
    "2": [1,1,0,1,1,0,1],
    "3": [1,1,1,1,0,0,1],
    "4": [0,1,1,0,0,1,1],
    "5": [1,0,1,1,0,1,1],
    "6": [1,0,1,1,1,1,1],
    "7": [1,1,1,0,0,0,0],
    "8": [1,1,1,1,1,1,1],
    "9": [1,1,1,1,0,1,1]
}

def draw_segment(x, y, seg_id, size, color):
    """Draw one segment polygon"""
    thickness = size // 6
    length = size

    if seg_id == 0:  # top
        coords = [(x, y), (x+length, y), (x+length-thickness, y+thickness), (x+thickness, y+thickness)]
    elif seg_id == 1:  # top-right
        coords = [(x+length, y), (x+length, y+length), (x+length-thickness, y+length-thickness), (x+length-thickness, y+thickness)]
    elif seg_id == 2:  # bottom-right
        coords = [(x+length, y+length), (x+length, y+2*length), (x+length-thickness, y+2*length-thickness), (x+length-thickness, y+length+thickness)]
    elif seg_id == 3:  # bottom
        coords = [(x, y+2*length), (x+length, y+2*length), (x+length-thickness, y+2*length-thickness), (x+thickness, y+2*length-thickness)]
    elif seg_id == 4:  # bottom-left
        coords = [(x, y+length), (x+thickness, y+length+thickness), (x+thickness, y+2*length-thickness), (x, y+2*length)]
    elif seg_id == 5:  # top-left
        coords = [(x, y), (x+thickness, y+thickness), (x+thickness, y+length-thickness), (x, y+length)]
    elif seg_id == 6:  # middle
        coords = [(x+thickness, y+length-thickness//2), (x+length-thickness, y+length-thickness//2),
                  (x+length, y+length), (x+length-thickness, y+length+thickness//2),
                  (x+thickness, y+length+thickness//2), (x, y+length)]
    else:
        return

    canvas.create_polygon(coords, fill=color, outline=color)

def draw_digit(x, y, digit, size=25, color_on="red", color_off="#220000"):
    segs = digit_segments[digit]
    for i in range(7):
        color = color_on if segs[i] else color_off
        draw_segment(x, y, i, size, color)

def update_clock():
    canvas.delete("all")
    now = strftime("%I:%M:%S %p")  # 12-hour format with AM/PM
    x = 10
    for ch in now:
        if ch == ":":
            # colon dots
            canvas.create_oval(x, 40, x+5, 50, fill="red", outline="red")
            canvas.create_oval(x, 70, x+5, 80, fill="red", outline="red")
            x += 20
        elif ch == " ":
            x += 20
        elif ch in ["A","P","M"]:
            canvas.create_text(x, 120, text=ch, fill="red", font=("Arial", 12, "bold"))
            x += 15
        else:
            draw_digit(x, 20, ch, size=25)
            x += 40
    root.after(1000, update_clock)

update_clock()
root.mainloop()

Step-by-Step Code Explanation

1. Tkinter Window Setup

We create a Tkinter window of size 300x200 with a black background. The Canvas widget is used to draw the segments and time display.

2. Digit Segment Mapping

Each digit (0–9) is represented by a list of 0 and 1, where each value indicates whether a segment should be ON or OFF. Example: "8": [1,1,1,1,1,1,1] means all 7 segments are lit.

3. Drawing Segments

The draw_segment() function creates polygon shapes for each segment (top, bottom, left, right, and middle). Depending on the digit, segments are either red (ON) or dim (OFF).

4. Updating the Clock

The update_clock() function:

  • Fetches current time using strftime("%I:%M:%S %p").
  • Draws each digit using the 7-segment display logic.
  • Adds colons and AM/PM text.
  • Runs every second with root.after(1000, update_clock).

Applications of This Project

  • A fun Python GUI project for beginners.
  • Can be used in Python desktop applications that need a digital clock.
  • Helps in understanding Canvas drawing and custom UI elements.
  • Good practice for time-based event handling in Tkinter.
🔗
Shah

Posted by Shah