Alarm Clock

#coding=utf-8  

import pyaudio  
import wave
import time
from datetime import datetime
import sys


def main():
    hour = input("Hour for the alarm to set: ")
    while int(hour) < 0 or int(hour) > 23:
        hour = input("Invalid hour.\nHour for the alarm to set: ")
    minute = input("Minute for the alarm to set: ")
    while int(minute) < 0 or int(minute) > 59:
        minute = input("Invalid minute.\nMinute for the alarm to set: ")
        
    alarm_time = str(hour) + ":" + str(minute)
    
    while True:
        if datetime.now().strftime('%H:%M') == datetime.strptime(alarm_time, '%H:%M').time().strftime('%H:%M'):
            play_alarm_sound()
            
            user_input = input("Do you want to set a new alarm? [Y/N]\n")
            if str(user_input) in ['y', 'Y']:
                hour = input("Hour for the alarm to set: ")
                
                while int(hour) < 0 or int(hour) > 23:
                    hour = input("Invalid hour.\nHour for the alarm to set: ")
                minute = input("Minute for the alarm to set: ")
                while int(minute) < 0 or int(minute) > 59:
                    minute = input("Invalid minute.\nMinute for the alarm to set: ")
                    
                alarm_time = str(hour) + ":" + str(minute)
            elif str(user_input) in ['n', 'N']:
                sys.exit()
            else:
                while str(user_input) not in ['y','Y', 'n', 'N']:
                    user_input = input("Do you want to set a new alarm? [Y/N]\n")
                if str(user_input) in ['y', 'Y']:
                    hour = input("Hour for the alarm to set: ")
                
                    while int(hour) < 0 or int(hour) > 23:
                        hour = input("Invalid hour.\nHour for the alarm to set: ")
                    minute = input("Minute for the alarm to set: ")
                    while int(minute) < 0 or int(minute) > 59:
                        minute = input("Invalid minute.\nMinute for the alarm to set: ")
                        
                    alarm_time = str(hour) + ":" + str(minute)
                else:
                    sys.exit()
            
        time.sleep(1)


def play_alarm_sound():
    chunk = 1024  

    f = wave.open("alarm.wav","rb")   
    p = pyaudio.PyAudio()  

    stream = p.open(format = p.get_format_from_width(f.getsampwidth()),  
                    channels = f.getnchannels(),  
                    rate = f.getframerate(),  
                    output = True)  

    data = f.readframes(chunk)  

    while data != b'':  
        stream.write(data)  
        data = f.readframes(chunk)  

    stream.stop_stream()  
    stream.close()  

    p.terminate()
    

if __name__ == "__main__":
    try:
        main()
    except ValueError:
        print("Not a number! Run the program again.")