Write an alarm clock program in Python

There are many types of exercises where you can improve your Python programming skills. One of them is the exercise of writing a simple alarm program. After writing, you can run the alarm program with the command.

Write an alarm clock program in Python

First, you must create a Python script and add commands to display a question asking when the user wants to set the alarm. If you're unfamiliar with some Python syntax, you can look at some Python examples to understand the fundamentals.

1. Create a new file and name it alarm.py.
2. Open the Python script with any text editor, such as Notepad++.
3. At the top of the file, import both the datetime and time modules. The program will use these modules to calculate how long it has to wait for the alarm to ring. You can use Python's time module to delay execution as well as other actions.

import datetime import time

1. Add a while loop, requiring the user to enter a valid alarm ringing time, in the correct [hour:minute] format. The while loop will repeat if the user enters an incorrect number.

invalid = True   while(invalid):     # Get a valid user input for the alarm time     print("Set a valid time for the alarm (Ex. 06:30)")     userInput = input(">> ")

1. In the while loop, convert the user input into an array that separates the hour value from the minute value.

  # For example, this will convert 6:30 to an array of [6, 30].     alarmTime = [int(n) for n in userInput.split(":")]

1. Still in the while loop, check the hour value and minute value. The hour value must be between 0 and 23, and the minute value must be between 0 and 59. If these conditions are not met, the while loop is repeated, requiring the user to enter a value new.

# Validate the time entered to be between 0 and 24 (hours) or 0 and 60 (minutes)     if alarmTime[0] >= 24 or alarmTime[0] < 0:         invalid = True     elif alarmTime[1] >= 60 or alarmTime[1] < 0:         invalid = True     else:         invalid = False

How to count the waiting time until the alarm rings

You create a counter for how many seconds the program will have to wait until the alarm goes off.

1. Below the while loop, convert the alarm time to the number of seconds in the day. For example, a day has 86,400 seconds. If the user enters 00:01 (one minute after midnight), the alarm time in seconds will be 60. If the user enters 23:59, the alarm time in seconds will be 86,340.

# Number of seconds in an Hour, Minute, and Second seconds_hms = [3600, 60, 1] # Convert the alarm time to seconds alarmSeconds = sum([a*b for a,b in zip(seconds_hms[:len(alarmTime)], alarmTime)])

1. Use the datetime.now() function to determine the current time. Convert current time to seconds:

now = datetime.datetime.now() currentTimeInSeconds = sum([a*b for a,b in zip(seconds_hms, [now.hour, now.minute, now.second])])

1. Calculate the number of seconds to wait until the alarm sounds:

secondsUntilAlarm = alarmSeconds - currentTimeInSeconds

1. If the difference between two time periods is negative, the alarm will be set for the next day:

if secondsUntilAlarm < 0:     secondsUntilAlarm += 86400 # number of seconds in a day

1. Display a message to let the user know the alarm has been successfully set:

print("Alarm is set!") print("The alarm will ring at %s" % datetime.timedelta(seconds=secondsUntilAlarm))

How to make the alarm sound

To ring the alarm, wait for the last seconds to pass before printing the message "Wake up!" for users.

1. Use time.sleep to set the number of seconds to wait before the alarm sounds:

time.sleep(secondsUntilAlarm)

1. Show a notification to the user when the alarm goes off:

print("Ring Ring. time to wake up!")

How to add a countdown timer before the alarm goes off

1. Replace the time.sleep line. Add a for loop for each second until the bell rings and display the remaining seconds to the user:

for i in range(0, secondsUntilAlarm):     time.sleep(1)     secondsUntilAlarm -= 1     print(datetime.timedelta(seconds=secondsUntilAlarm))

How to run the alarm program

You run the alarm program by navigating to where the file is saved using the command line. Use the Python command to run the program and enter the alarm time.

1. Open Commnad Prompt or Terminal. Navigate to where you saved the alarm.py file. For example, if you save a Python file on the Desktop, you use the cd Desktop command.

cd Desktop

1. Use Python command to run Python program:

python alarm.py

1. Set the exact timer time in [hour:minute] format, for example 4:30.

1. The alarm clock will be set and start counting down every second until the bell rings. Wait until the alarm clock completes the countdown.

1. When the countdown ends, the program will display a message letting you know that the bell is ringing.

Writing an alarm clock program in Python is a simple exercise that will help you improve your Python programming skills. TipsMake.com hopes that this article will be useful to you.

Isabella Humphrey

Update 17 October 2023