good job

"""

Write a program that calculates the digital root of a given number.

The digital root is the single-digit value obtained by an iterative process of summing digits,

on each iteration using the result from the previous iteration to compute a digit sum.

The process continues until a single-digit number is obtained.

For example, the digital root of 456 is calculated as follows:

4 + 5 + 6 = 15

1 + 5 = 6

So, the digital root of 456 is 6.

"""

 

 

 

문제가 진짜 진짜 쉬워보이는데 
생각보다 난이도가 있네요 
아무것도 쓰지 않고 암산으로만 풀어보세요 
아래 코드를 보지 말고 위에 문제만 보시고 스스로 풀어보세용~ 

 

 

 

 

 

def is_less_than_tenth(num):

    return isinstance(num, int) and 0 <= num < 10

x = int(input('Please give me any number: '))

result = 0

while True:

    leng = len(str(x))

    for i in range(1, leng + 1):

        temp = (x % (10 ** (leng - i + 1))) // (10 ** (leng - i))

        result += temp

        x -= temp * (10 ** (leng - i))

    if is_less_than_tenth(result):

        break

    x = result

    result = 0

print('Digital root:', result)