In this tutorial, we will learn how to create a simple stopwatch using Python tkinter. We’ll build a basic GUI with start, stop, and reset buttons to track a real Python GUI application.
Let’s begin.
Stopwatch
- The stopwatch is a simple counting of numbers.
- It is timed in seconds & helps the user to understand how much time he/she took to complete the task.
- Later, these deviations in time are analyzed & further plans are set.
- No competition is possible without a stopwatch.
Overview of Stopwatch in Python
- The stopwatch can be of two types:
- Forward counting
- backward counting
- Forward-counting stopwatch keeps on increasing till infinite seconds if reset or stop is not pressed.
- Backward Stopwatch is provided with a number & it moves in the decreasing order until it becomes zero.
- Backward Stopwatch is also called Countdown watch.
- We Separate post for Countdown watch.
- In this section, we will talk about forwarding stopwatch.
- Stopwatch has Start, Stop & Reset options.
- Start button starts or resumes the count on the display
- Stop button stops the count then & there.
- Reset button sets the timer back to 0 or the starting point.
Read Create Tables in Python Tkinter
Stopwatch source code in Python
In this section, we will explain the easy way to code a stopwatch in Python. It is recommended to please go throw the entire blog.
Step 1:
Import everything from the tkinter module
from tkinter import *Step 2:
Configure the Main application window
ws = Tk()
ws.geometry('400x450+1000+300')
ws.title('PythonGuides: Stopwatch')
ws.config(bg='#299617')
ws.iconbitmap('stopwatch.ico')
ws.resizable(0,0)- The main application window is created & named as ws, which is the shorthand for workspace.
- Geometry includes the size & position of the window.
- Here, 400 is the width of the main application.
- 450 is the height of the main application.
- 1000 is the x position of the main application.
- 300 is the y position of the main application.
- The title is the text appearing on the top of the main application window.
- ws.config(bg=’colorname or hex code’) this code is used to set the background colour of the main application.
- iconbitmap is used to set the icon on the main application window. The default icon is a feature.
- resizable determines the amount window that can be stretched by the user.
- It accepts x and y values
- In this case value is 0, 0, which means the window can’t be resized.
Step 3: Place an image of a Stopwatch
bg = PhotoImage(file='stopwatch.png')
img = Label(ws, image=bg, bg='#299617')
img.place(x=75, y=50)- We have created an image using logomakr.com
- bg stores the image that is obtained using PhotoImage
- The image is placed on the Label using the image option
- Refer to our label section to know more about the Label.
Step 4:
Placing buttons on the main application window.
start_btn=Button(
ws,
text='Start',
width=15,
command=lambda:StartTimer(lbl)
)
start_btn.place(x=30, y=390)- Buttons are meant to perform an action
- To understand the button, please refer to our button section
- Here, we will look at the command option, the command is the action that will be performed when the button is clicked.
- We have created an independent function for start, stop & reset that takes a parameter.
- In the button using the command keyword, we can pass the function, but the catch is that we cannot pass a parameter to that function. So to do that, we use the anonymous function lambda.
Step 5:
Creating Global Variables
counter = -1
running = False- Python Variables used in a function are limited to that function only
- If we want to use a particular variable in another function, then we have to declare that variable as a global variable.
- In this stopwatch source code in Python, we have declared counter & running as global variables.
- Any function referring to these variables must use the global keyword before the variable name
- These two variables are later used in multiple functions.
- Changes made by any function on these variables will be observed by other functions too.
- For example, if any function sets the value of the counter to 10, then other functions using the counter will also have the counter value as 10.
Step 6:
Explaining functions
- counter_label() and count()
def counter_label(lbl):
def count():
if running:
global counter
if counter==-1:
display="00"
else:
display=str(counter)
lbl['text']=display
lbl.after(1000, count)
counter += 1
count() - In this code, the counter_label is accepting the argument label.
- count() is another function passed in counter_label.
- if running means if running == True, below program under the if statement will work till the time running is true.
- The counting of the number will stop when running is set to false
- Global counter, here we are calling the variable counter, which is outside this function.
- Till the time counter is -1, it will display 00 on the screen.
- The moment the user clicks on the action button, this function will be activated, and the counter will keep on increasing from -1 to n.
- This increment in the counter will take place every 1000 milliseconds.
- In the end, this function will return the current counter time
- StartTimer()
def StartTimer(lbl):
global running
running=True
counter_label(lbl)
start_btn['state']='disabled'
stop_btn['state']='normal'
reset_btn['state']='normal'- This is the function that will be called when user will user clicks on the start button.
- counter_label function is called inside this function.
- Every time the start button is clicked, it will be disabled immediately & the user won’t be able to click it again.
- Also, it enables stop and reset buttons. That means users can click on these buttons.
StopTimer()
def StopTimer():
global running
start_btn['state']='normal'
stop_btn['state']='disabled'
reset_btn['state']='normal'
running = False- These functions will be called when the user clicks on the stop button.
- This will set the running to false.
- That means the activity happening in the counter_label() function will stop now.
- Also, it will disable the stop button & the user won’t be able to click it again.
- and will enable the start & reset buttons.
- So now the user can either resume the counter by clicking on the start button or reset it.
ResetTimer()
def ResetTimer(lbl):
global counter
counter=-1
if running==False:
reset_btn['state']='disabled'
lbl['text']='00'
else:
lbl['text']=''- The reset function is called when the user clicks on the Reset button.
- The counter will again be set to the default value, i.e, -1
- Running will be set to false, and text appearing on the main application window will be set to 00.
- So in this way, everything will start appearing similar to the screen that appeared when the program was run.
Code:
from tkinter import *
ws = Tk()
ws.geometry('400x450+1000+300')
ws.title('PythonGuides: Stopwatch')
ws.config(bg='#299617')
ws.iconbitmap('stopwatch.ico')
ws.resizable(0,0)
counter = -1
running = False
def counter_label(lbl):
def count():
if running:
global counter
if counter==-1:
display="00"
else:
display=str(counter)
lbl['text']=display
lbl.after(1000, count)
counter += 1
count()
def StartTimer(lbl):
global running
running=True
counter_label(lbl)
start_btn['state']='disabled'
stop_btn['state']='normal'
reset_btn['state']='normal'
def StopTimer():
global running
start_btn['state']='normal'
stop_btn['state']='disabled'
reset_btn['state']='normal'
running = False
def ResetTimer(lbl):
global counter
counter=-1
if running==False:
reset_btn['state']='disabled'
lbl['text']='00'
else:
lbl['text']=''
bg = PhotoImage(file='stopwatch.png')
img = Label(ws, image=bg, bg='#299617')
img.place(x=75, y=50)
lbl = Label(
ws,
text="00",
fg="black",
bg='#299617',
font="Verdana 40 bold"
)
label_msg = Label(
ws, text="minutes",
fg="black",
bg='#299617',
font="Verdana 10 bold"
)
lbl.place(x=160, y=170)
label_msg.place(x=170, y=250)
start_btn=Button(
ws,
text='Start',
width=15,
command=lambda:StartTimer(lbl)
)
stop_btn = Button(
ws,
text='Stop',
width=15,
state='disabled',
command=StopTimer
)
reset_btn = Button(
ws,
text='Reset',
width=15,
state='disabled',
command=lambda:ResetTimer(lbl)
)
start_btn.place(x=30, y=390)
stop_btn.place(x=150, y=390)
reset_btn.place(x=270, y=390)
ws.mainloop()Output:
In this article, I have explained to you how to stopwatch using Python tkinter. I discussed an overview of a stopwatch in Python and a stopwatch source code with an explanation of all the terms I have used. Hope you understood the code and its explanation.
You may like the following Python tutorials:
- Create a Python Tkinter Text Editor
- Create Animations in Python with Tkinter
- Master Python Tkinter Events
Bijay Kumar is an experienced Python and AI professional who enjoys helping developers learn modern technologies through practical tutorials and examples. His expertise includes Python development, Machine Learning, Artificial Intelligence, automation, and data analysis using libraries like Pandas, NumPy, TensorFlow, Matplotlib, SciPy, and Scikit-Learn. At PythonGuides.com, he shares in-depth guides designed for both beginners and experienced developers. More about us.
