Creating a Simple Countdown Timer with Tkinter

Introduction

• Briefly explain Tkinter as a GUI toolkit for Python.

• Introduce the project: A countdown timer with start, pause, and reset functionality.

Setting Up Tkinter

Mention that Tkinter comes pre-installed with Python, so no extra installation is needed.

The Code

from tkinter import *
import time
def start_timer():
    global running, time_left
    if not running:
        running = True
        countdown()
def pause_timer():
    global running
    running = False
def reset_timer():
    global running, time_left
    running = False
    time_left = int(e1.get()) if e1.get().isdigit() else 0
    l2.config(text=f"Time Left: {time_left}s")
def countdown():
    global time_left
    if running and time_left > 0:
        time_left -= 1
        l2.config(text=f"Time Left: {time_left}s")
        b.after(1000, countdown)
# Main Window
b = Tk()
b.title("Simple Timer")
b.geometry("300x200")
running = False
# Input Field for Time
l1 = Label(b, text="Enter Time (seconds):")
l1.pack()
e1 = Entry(b)
e1.pack()
time_left = 0
# Timer Display
l2 = Label(b, text=f"Time Left: {time_left}s", font=("Arial", 14))
l2.pack()
# Buttons
b1 = Button(b, text="Start", command=start_timer)
b1.pack()
b2 = Button(b, text="Pause", command=pause_timer)
b2.pack()
b3 = Button(b, text="Reset", command=reset_timer)
b3.pack()
b.mainloop()
from tkinter import *
import time

def start_timer():
    global running, time_left
    if not running:
        running = True
        countdown()

def pause_timer():
    global running
    running = False

def reset_timer():
    global running, time_left
    running = False
    time_left = int(e1.get()) if e1.get().isdigit() else 0
    l2.config(text=f"Time Left: {time_left}s")

def countdown():
    global time_left
    if running and time_left > 0:
        time_left -= 1
        l2.config(text=f"Time Left: {time_left}s")
        b.after(1000, countdown)

# Main Window
b = Tk()
b.title("Simple Timer")
b.geometry("300x200")

running = False

# Input Field for Time
l1 = Label(b, text="Enter Time (seconds):")
l1.pack()
e1 = Entry(b)
e1.pack()

time_left = 0

# Timer Display
l2 = Label(b, text=f"Time Left: {time_left}s", font=("Arial", 14))
l2.pack()

# Buttons
b1 = Button(b, text="Start", command=start_timer)
b1.pack()
b2 = Button(b, text="Pause", command=pause_timer)
b2.pack()
b3 = Button(b, text="Reset", command=reset_timer)
b3.pack()

b.mainloop()
from tkinter import *
import time

def start_timer():
    global running, time_left
    if not running:
        running = True
        countdown()

def pause_timer():
    global running
    running = False

def reset_timer():
    global running, time_left
    running = False
    time_left = int(e1.get()) if e1.get().isdigit() else 0
    l2.config(text=f"Time Left: {time_left}s")

def countdown():
    global time_left
    if running and time_left > 0:
        time_left -= 1
        l2.config(text=f"Time Left: {time_left}s")
        b.after(1000, countdown)

# Main Window
b = Tk()
b.title("Simple Timer")
b.geometry("300x200")

running = False

# Input Field for Time
l1 = Label(b, text="Enter Time (seconds):")
l1.pack()
e1 = Entry(b)
e1.pack()

time_left = 0

# Timer Display
l2 = Label(b, text=f"Time Left: {time_left}s", font=("Arial", 14))
l2.pack()

# Buttons
b1 = Button(b, text="Start", command=start_timer)
b1.pack()
b2 = Button(b, text="Pause", command=pause_timer)
b2.pack()
b3 = Button(b, text="Reset", command=reset_timer)
b3.pack()

b.mainloop()

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Code Explanation

1. Explain each function:

• start_timer(): Starts the countdown.
• pause_timer(): Pauses the countdown.
• reset_timer(): Resets the time to the user’s input.
• countdown(): Decreases the time and updates the label every second.

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原文链接：Creating a Simple Countdown Timer with Tkinter