enahasment: add spy number in maths-special numbers

Author: BhaktiVagadia

maths/special_numbers/spy_number.py

@@ -0,0 +1,48 @@
+"""
+== Spy Number ==
+ spy number is defined as a positive integer where the
+ sum of its digits equals the product of its digits.
+
+Examples of Spy Numbers: 22,123,1124,...
+https://www.scribd.com/document/895653665/Interesting-Number-Programs
+"""
+def is_spy_number(number: int) -> bool:
+    """
+    This functions takes an integer number as input.
+    returns True if the number is spy.
+    >>> is_spy_number(-1)
+    False
+    >>> is_spy_number(0)
+    False
+    >>> is_spy_number(22)
+    True
+    >>> is_spy_number(1124)
+    True
+    >>> is_spy_number(124)
+    False
+    >>> is_spy_number(5.0)
+    Traceback (most recent call last):
+        ...
+    TypeError: Input value of [number=5.0] must be an integer
+    """
+    if not isinstance(number, int):
+        msg = f"Input value of [number={number}] must be an integer"
+        raise TypeError(msg)
+    if number <= 0:
+        return False
+    digit_sum = 0
+    digit_mul = 1
+    while number > 0:
+        digit = number % 10
+        digit_sum += digit
+        digit_mul *= digit
+        number //= 10
+    if digit_sum == digit_mul:
+        return True
+    return False
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()