while loop won't works right in python-CodePudding

I wrote this code for summing up digits of a number which is bigger than 10 until the result only have one digit and when I try to compile it, it won't even give me an error until I stop it. I want to know what's the problem.

number = input()
#sumed_up_digits = result
result = 0

while len(number) != 1:
    for i in number:
        int_i = int(i)
        result = result   int_i

     number = str(result)

print(result)

CodePudding user response：

Try the following code:

   s=input()
   n=len(s)
   result=0
   for i in range(n-1):
      result=result int(s[i])
   print(result)

This for loop runs from 0th to (n-2)th index of the given string, hence the last digit will not be added to the result. Like for 1245, it will add 1,2 and 4 to result, but not 5.

CodePudding user response：

result is cumulative and include previous sums. try:

number = input()
#sumed_up_digits = sum
sum = 0

while len(number) != 1:
    result = 0
    for i in number:
        int_i = int(i)
        result = result   int_i
    sum = sum   result
    number = str(result)

print(sum)

CodePudding user response：

You can do it like this:

number = input()

if len(number) <= 1:
    print(0)

while len(number) > 1:
    number = str(sum(int(i) for i in number))

print(int(number))

Of course, you would need to check that the initial input number is made of digits...

CodePudding user response：

the problem is number isn't being shortened so the condition for the loop to stop is never reached.

number = input()

result = 0
while len(number) != 1:
    # set digit to last number
    digit = int(number) % 10
    result  = digit
    number = number[:-1]

print(result)