Improve readability of factorial implementation

maths/factorial.py

@@ -1,6 +1,4 @@
-"""
-Factorial of a positive integer -- https://en.wikipedia.org/wiki/Factorial
-"""
+"""FACTORIAL."""
 
 
 def factorial(number: int) -> int:
@@ -27,16 +25,19 @@ def factorial(number: int) -> int:
     """
     if number != int(number):
         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:
+def factorial_recursive(number: int) -> int:
     """
+
     Calculate the factorial of a positive integer
     https://en.wikipedia.org/wiki/Factorial
 
@@ -51,18 +52,21 @@ def factorial_recursive(n: int) -> int:
     Traceback (most recent call last):
         ...
     ValueError: factorial() not defined for negative values
+
     """
-    if not isinstance(n, int):
+
+    if not isinstance(number, int):
         raise ValueError("factorial() only accepts integral values")
-    if n < 0:
+
+    if number < 0:
         raise ValueError("factorial() not defined for negative values")
-    return 1 if n in {0, 1} else n * factorial_recursive(n - 1)
+    return 1 if number in {0, 1} else number * factorial_recursive(number - 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)}")
+    number = int(input("Enter a positive integer: ").strip() or 0)
+    print(f"factorial{number} is {factorial(number)}")