Why Pythonw file is taking big CPU resources?

Question

I write a .pyw file and run it on background. But, when I do nothing, it takes 29% CPU. If I start any other software, it starts to take 49% - 50% CPU. Is there any way to reduce the CPU usage?

Code:

def check():
    time = str(datetime.datetime.now())
    time = time[11:13] + time[14:16]
    today = str(datetime.datetime.today())
    today = today[:4] + today[5:7] + today[8:10]
    
    file = open("alarms\\Today\\today.txt", "r")
    alarms = file.readlines()
    file.close()
    
    ID = ""
    hasAlarm = False
    i = 0
    while i < len(alarms):
        if time in alarms[i]:
            hasAlarm = True
            ID = alarms[i+1]
            break
        i += 2
    
    if hasAlarm:
        file = open("alarms\\ID\\alarmID.txt", "r")
        alarms = file.readlines()
        file.close()
        i = 0
        while i < len(alarms):
            if ID in alarms[i]:
                break
            i += 6
        name = alarms[i+1][:-1]
        showtime = change24to12(alarms[i+2][:-1])
        if os.path.exists(alarms[i+5][:-1]):
            ringtone = alarms[i+5][:-1]
        else:
            ringtone = "basic.mp3"
        
        app = QApplication(sys.argv)
        window = AlarmWindow(name, showtime, ringtone)

        file = open("alarms\\Today\\today.txt", "r")
        alarms = file.readlines()
        file.close()
        file = open("alarms\\Today\\today.txt", "w")
        file.writelines(alarms[2:])
        file.close()
        
        file = open("alarms\\Special Days\\" + today + ".txt", "r")
        alarms = file.readlines()
        file.close()
        i = 0
        flag = False
        while i < len(alarms):
            if time in alarms[i]:
                flag = True
                break
            i += 2
        if flag:
            file = open("alarms\\Special Days\\" + today + ".txt", "w")
            file.writelines(alarms[:i] + alarms[i+2:])
            file.close()

        notification.notify(title=name, message=showtime)

        app.exec()
while True:
    check()

I want that the infinite loop will run and call the function from the background.

Apart from my eyes now bleeding, you execute your code as fast as possible over and over again. Simplest solution, make it stop for a second: https://docs.python.org/3/library/time.html#time.sleep --- For opening files, use `with`: https://docs.python.org/3/tutorial/inputoutput.html#reading-and-writing-files -- Since you spawn a whole QtApp for a notification, you could just have everything execute in a QtApp and use Qt timers. — user136036, Nov 01 '20 at 12:36
@user136036 ha ha! :P But can you elaborate how using with instead of normal file open can save time? — Debtanu Gupta, Nov 01 '20 at 12:40
@user136036 and how time.sleep(1) is reducing the CPU usage internally? — Debtanu Gupta, Nov 01 '20 at 12:44
`with` is just best practice and saves a useless `close`. Well, when the program sleeps it uses no CPU... — user136036, Nov 01 '20 at 12:46

Why Pythonw file is taking big CPU resources?

0 Answers0