fun-div-by-nine.py

from sys import argv

n = argv[1]

co_dividend = 0
dec_expansion = 0
pow_max = len(n) - 2 # Last iteration should be pow == 0, first it should be the highest
for (i,c) in enumerate(n[:-1]): # Ignore last digit
    pow_i = pow_max - i
    co_dividend += int(c) # Sum of all digits
    dec_expansion += co_dividend * (10 ** pow_i) # Our result will be part of this expansion
c = n[-1]
co_dividend += int(c)

carry_over = int(co_dividend / 9)
reminder = int(co_dividend % 9)
result = dec_expansion + carry_over
print(f"res: {result} , reminder: {reminder}")