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
I am Bijay Kumar, a Microsoft MVP in SharePoint. Apart from SharePoint, I started working on Python, Machine learning, and artificial intelligence for the last 5 years. During this time I got expertise in various Python libraries also like Tkinter, Pandas, NumPy, Turtle, Django, Matplotlib, Tensorflow, Scipy, Scikit-Learn, etc… for various clients in the United States, Canada, the United Kingdom, Australia, New Zealand, etc. Check out my profile.
