maths.digital_root

Functions

digital_root(→ int)

Return the digital root of a non-negative integer number.

Module Contents

maths.digital_root.digital_root(number: int) → int

Return the digital root of a non-negative integer number.

The digital root is the single-digit value obtained by repeatedly summing the decimal digits of number until only one digit remains. The input is taken by its absolute value, so negative numbers behave like their positive counterpart.

>>> digital_root(0)
0
>>> digital_root(9)
9
>>> digital_root(38)
2
>>> digital_root(12345)
6
>>> digital_root(-45)
9
>>> digital_root(999999999999)
9