WebMD may need to derive a simple numeric checksum from an integer, such as a compact value associated with a health content identifier. Given an integer, return the sum of the digits in its absolute value.
Do not convert the number to a string. Use arithmetic operations to extract each digit.
Implement sum_digits(number), where number is an integer. Return an integer equal to the sum of all decimal digits in abs(number). For example, the digit sum of -508 is 5 + 0 + 8 = 13.
A value of 0 has a digit sum of 0.
def sum_digits(number):