We read the input as string ( by default ) and as string is an iterable object we can find the each digit ( char as a string ) by using the position starting from 0 as first position.
In next step covert each char to integer by int() function and then add them all to get the sum of the digits.
Video Tutorial on Sum of digits of a number
n=input("Enter a Number :")
for i in range(0,len(n)):
print("sum of digits in number : ", sum)
Enter a Number :549
sum of digits in number : 18
In above code we used len() to get the number of elements ( or char here ) in the string object n.
To any number if we divide by 10 then reminder will be the right most digit.
If 4534 is divided by 10 then reminder is 4 ( the right most digit ).
The floor value of 4534 after the division by 10 will be 453, so we can loop through and find the floor values till the floor value became 0. Inside the loop we can get reminders as digits of the number. Here is the code.
n=int(input("Enter a Number :"))
i=n%10 # reminder value of division
n=n//10 # floor value of division
print("sum of digits in number=",sum)