Create digitial_root.py

maths/digitial_root.py

@@ -0,0 +1,28 @@
+"""
+digital_root.py
+----------------
+Calculates the digital root of a given number.
+
+A digital root is obtained by summing the digits of a number repeatedly
+until only a single-digit number remains.
+
+Example:
+    >>> digital_root(942)
+    6
+    >>> digital_root(132189)
+    6
+    >>> digital_root(493193)
+    2
+"""
+
+
+def digital_root(n: int) -> int:
+    """Return the digital root of a non-negative integer."""
+    while n >= 10:
+        n = sum(map(int, str(n)))
+    return n
+
+
+if __name__ == "__main__":
+    num = int(input("Enter a number: "))
+    print(digital_root(num))