Countdown Timer using PyQt5 in Python

This article will demonstrate how to build a countdown timer application using PyQt5. When using a timer, which is a particular sort of clock used to measure certain time intervals, we must count down from the supplied time until it reaches zero.

Steps for implementing a GUI :

Make a push button that opens a pop-up window for time display and configure its shape.
Label the time and the status of completion.
Set the label's size, font, and text alignment to centre.
Make three push buttons: one for the timer's start, one for its pause, and one for its reset.
Set each button's geometry.

Implementation procedure for the back end :

Create a count variable and a flag to indicate whether the counter is running or not.
Give each button a function.
Get the value of the second using the input dialogue box within the get second button action, then set the flag to false.
Make the flag true within the start action, but if the count is zero, make the if false.
Inside the pause action, set the flag to false.
Set the count value to zero, the flag to false, and the label's text as part of the reset process.
Create an object called a timer that calls its method every 100 milliseconds.
Check for the flag inside the timer action, then reduce the value of the count and set the label's content.

Walking through the code :

First, import all the required libraries into the program.

# import all the required modules
from PyQt5.QtWidgets import *
from PyQt5 import QtCore, QtGui
from PyQt5.QtGui import *
from PyQt5.QtCore import *
import sys

Next, create a class to initialise the window and set its properties.

class Window(QMainWindow):

	def __init__(self):
		super().__init__()

		# set the window title
		self.setWindowTitle("Python ")

		# set the window geometry
		self.setGeometry(100, 100, 400, 600)

		# call the components method
		self.UiComponents()

		# displaying all the present widgets
		self.show()

Then, create a method to introduce all components, add buttons and add labels to display text.

# function for the widgets
	def UiComponents(self):

		# introducing the variables
		# create a count variable
		self.count = 0

		# starting value of flag
		self.start = False

		# create a push button for getting the time in seconds
		btn = QPushButton("Set time(s)", self)

		# set the geometry of the push button
		btn.setGeometry(125, 100, 150, 50)

		# add action to the push button for being clicked
		btn.clicked.connect(self.get_seconds)

		# create a new label to display the seconds
		self.label = QLabel("//TIMER//", self)

		# set the geometry for the label
		self.label.setGeometry(100, 200, 200, 50)

		# set the label's borders
		self.label.setStyleSheet("border : 3px solid black")

		# set the font for the label
		self.label.setFont(QFont('Times', 15))

		# set the alignment for the label
		self.label.setAlignment(Qt.AlignCenter)

		# create a new start button
		start_btn = QPushButton("Start", self)

		# set the geometry for the start button
		start_btn.setGeometry(125, 350, 150, 40)

		# add action to the start button
		start_btn.clicked.connect(self.start_actn)

		# create a new pause button
		pause_btn = QPushButton("Pause", self)

		# set the geometry for the pause button
		pause_btn.setGeometry(125, 400, 150, 40)

		# add action to the button
		pause_btn.clicked.connect(self.pause_actn)

		# create a new reset button
		reset_btn = QPushButton("Reset", self)

		# set the geometry for the reset button
		reset_btn.setGeometry(125, 450, 150, 40)

		# add action to the reset button
		reset_btn.clicked.connect(self.reset_actn)
		
           # create a new timer clock object
		timerClock = QTimer(self)

		# add action to the timer clock
		timerClock.timeout.connect(self.displayTime)

		# updating the timer clock after every tenth of a second
		timerClock.start(100)

Then, create the functions to be called when different buttons are clicked and what should the action done after that.

	# function to be called by the timer clock
	def displayTime(self):

		# check if the flag value is true
		if self.start:
			# increasing the counter
			self.count -= 1

			# timer clock is completed
			if self.count == 0:

				# converting the flag value to false
				self.start = False

				# set the text for the label
				self.label.setText("Completed !!!! ")

		if self.start:
			# get the text from the count
			txt = str(self.count / 10) + " s"

			# displaying the text
			self.label.setText(txt)


	# func to be called by the push button
	def get_scnds(self):

		# converting the flag value to false
		self.start = False

		# get the seconds and the flag value
		second, done = QInputDialog.getInt(self, 'Seconds', 'Enter Seconds:')

		# if the flag value is true
		if done:
			# improvising the value of the count variable
			self.count = second * 10

			# set the text for the label
			self.label.setText(str(second))

	def start_actn(self):
		# changing the flag value to true
		self.start = True

		# count = 0
		if self.count == 0:
			self.start = False

	def pause_actn(self):

		# changing the flag value to false
		self.start = False

	def reset_actn(self):

		# change the flag value to false
		self.start = False

		# set the count value to 0
		self.count = 0

		# set the label's text
		self.label.setText("//TIMER//")

Lastly, create an instance of the window to be displayed and execute the application.

# creating the pyqt5 application
Base = QApplication(sys.argv)

# creating an instance of the of Window created
window = Window()

# starting the application
sys.exit(Base.exec())

Complete code for the project :

# Python program to create a countdown timer using PyQt5
# import all the required modules
from PyQt5.QtWidgets import *
from PyQt5 import QtCore, QtGui
from PyQt5.QtGui import *
from PyQt5.QtCore import *
import sys


class Window(QMainWindow):

	def __init__(self):
		super().__init__()

		# set the window title
		self.setWindowTitle("Python ")

		# set the window geometry
		self.setGeometry(100, 100, 400, 600)

		# call the components method
		self.UiComponents()

		# displaying all the present widgets
		self.show()

	# function for the widgets
	def UiComponents(self):

		# introducing the variables
		# create a count variable
		self.count = 0

		# starting value of flag
		self.start = False

		# create a push button for getting the time in seconds
		btn = QPushButton("Set time(s)", self)

		# set the geometry of the push button
		btn.setGeometry(125, 100, 150, 50)

		# add action to the push button for being clicked
		btn.clicked.connect(self.get_seconds)

		# create a new label to display the seconds
		self.label = QLabel("//TIMER//", self)

		# set the geometry for the label
		self.label.setGeometry(100, 200, 200, 50)

		# set the label's borders
		self.label.setStyleSheet("border : 3px solid black")

		# set the font for the label
		self.label.setFont(QFont('Times', 15))

		# set the alignment for the label
		self.label.setAlignment(Qt.AlignCenter)

		# create a new start button
		start_btn = QPushButton("Start", self)

		# set the geometry for the start button
		start_btn.setGeometry(125, 350, 150, 40)

		# add action to the start button
		start_btn.clicked.connect(self.start_actn)

		# create a new pause button
		pause_btn = QPushButton("Pause", self)

		# set the geometry for the pause button
		pause_btn.setGeometry(125, 400, 150, 40)

		# add action to the button
		pause_btn.clicked.connect(self.pause_actn)

		# create a new reset button
		reset_btn = QPushButton("Reset", self)

		# set the geometry for the reset button
		reset_btn.setGeometry(125, 450, 150, 40)

		# add action to the reset button
		reset_btn.clicked.connect(self.reset_actn)

		# create a new timer clock object
		timerClock = QTimer(self)

		# add action to the timer clock
		timerClock.timeout.connect(self.displayTime)

		# updating the timer clock after every tenth of a second
		timerClock.start(100)

	# function to be called by the timer clock
	def displayTime(self):

		# check if the flag value is true
		if self.start:
			# increasing the counter
			self.count -= 1

			# timer clock is completed
			if self.count == 0:

				# converting the flag value to false
				self.start = False

				# set the text for the label
				self.label.setText("Completed !!!! ")

		if self.start:
			# get the text from the count
			txt = str(self.count / 10) + " s"

			# displaying the text
			self.label.setText(txt)


	# func to be called by the push button
	def get_scnds(self):

		# converting the flag value to false
		self.start = False

		# get the seconds and the flag value
		second, done = QInputDialog.getInt(self, 'Seconds', 'Enter Seconds:')

		# if the flag value is true
		if done:
			# improvising the value of the count variable
			self.count = second * 10

			# set the text for the label
			self.label.setText(str(second))

	def start_actn(self):
		# changing the flag value to true
		self.start = True

		# count = 0
		if self.count == 0:
			self.start = False

	def pause_actn(self):

		# changing the flag value to false
		self.start = False

	def reset_actn(self):

		# change the flag value to false
		self.start = False

		# set the count value to 0
		self.count = 0

		# set the label's text
		self.label.setText("//TIMER//")



# creating the pyqt5 application
Base = QApplication(sys.argv)

# creating an instance of the of Window created
window = Window()

# starting the application
sys.exit(Base.exec())

Output:

The output of the above mentioned code is attached below in the form of a screenshot.