fix-factorial-validation: Fix input validation and doctests

Fix factorial() input validation to use isinstance(number, int) instead of value comparison

Changes:
- Replace 'number != int(number)' with 'not isinstance(number, int)' in factorial()
- Fix doctests in factorial_recursive() to reference factorial_recursive() instead of factorial()
- Add negative test case for factorial(1.5) to verify non-integer rejection

This ensures consistent input validation between factorial() and factorial_recursive() functions.

Author: MathewAddala

maths/factorial.py

@@ -1,19 +1,20 @@
 """
 Factorial of a positive integer -- https://en.wikipedia.org/wiki/Factorial
 """
-
-
 def factorial(number: int) -> int:
     """
     Calculate the factorial of specified number (n!).
-
     >>> import math
     >>> all(factorial(i) == math.factorial(i) for i in range(20))
     True
     >>> factorial(0.1)
     Traceback (most recent call last):
         ...
     ValueError: factorial() only accepts integral values
+    >>> factorial(1.5)
+    Traceback (most recent call last):
+        ...
+    ValueError: factorial() only accepts integral values
     >>> factorial(-1)
     Traceback (most recent call last):
         ...
@@ -25,29 +26,30 @@ def factorial(number: int) -> int:
     >>> factorial(0)
     1
     """
-    if number != int(number):
+    if not isinstance(number, int):
         raise ValueError("factorial() only accepts integral values")
     if number < 0:
         raise ValueError("factorial() not defined for negative values")
     value = 1
     for i in range(1, number + 1):
         value *= i
     return value
-
-
 def factorial_recursive(n: int) -> int:
     """
     Calculate the factorial of a positive integer
     https://en.wikipedia.org/wiki/Factorial
-
     >>> import math
-    >>> all(factorial(i) == math.factorial(i) for i in range(20))
+    >>> all(factorial_recursive(i) == math.factorial(i) for i in range(20))
     True
-    >>> factorial(0.1)
+    >>> factorial_recursive(0.1)
     Traceback (most recent call last):
         ...
     ValueError: factorial() only accepts integral values
-    >>> factorial(-1)
+    >>> factorial_recursive(1.5)
+    Traceback (most recent call last):
+        ...
+    ValueError: factorial() only accepts integral values
+    >>> factorial_recursive(-1)
     Traceback (most recent call last):
         ...
     ValueError: factorial() not defined for negative values
@@ -57,12 +59,8 @@ def factorial_recursive(n: int) -> int:
     if n < 0:
         raise ValueError("factorial() not defined for negative values")
     return 1 if n in {0, 1} else n * factorial_recursive(n - 1)
-
-
 if __name__ == "__main__":
     import doctest
-
     doctest.testmod()
-
     n = int(input("Enter a positive integer: ").strip() or 0)
     print(f"factorial{n} is {factorial(n)}")