Improve Formatting and Code Quality (#934)

* Improved Formatting of basic_maths.py

- Added docstrings.
- Improved whitespace formatting.
- Renamed functions to match snake_case.

* Improved Formatting of factorial_python.py

- Added docstrings.
- Improved whitespace formatting.
- Renamed constants to match UPPER_CASE.

* Improved Formatting of factorial_recursive.py

- Improved whitespace formatting to meet PyLint standards.

* Improved Code to Conform to PyLint

- Renamed `max` to `max_num` to avoid redefining built-in 'max' [pylint]
- Removed unnecessary parens after 'while' keyword [pylint]

* Improved Formatting of factorial_recursive.py

- Added docstrings.
- Improved whitespace formatting.

maths/factorial_python.py

@@ -1,19 +1,19 @@
-# Python program to find the factorial of a number provided by the user.
+"""Python program to find the factorial of a number provided by the user."""
 
 # change the value for a different result
-num = 10
+NUM = 10
 
 # uncomment to take input from the user
-#num = int(input("Enter a number: "))
+# num = int(input("Enter a number: "))
 
-factorial = 1
+FACTORIAL = 1
 
 # check if the number is negative, positive or zero
-if num < 0:
-   print("Sorry, factorial does not exist for negative numbers")
-elif num == 0:
-   print("The factorial of 0 is 1")
+if NUM < 0:
+    print("Sorry, factorial does not exist for negative numbers")
+elif NUM == 0:
+    print("The factorial of 0 is 1")
 else:
-   for i in range(1,num + 1):
-       factorial = factorial*i
-   print("The factorial of",num,"is",factorial)
+    for i in range(1, NUM + 1):
+        FACTORIAL = FACTORIAL * i
+    print("The factorial of", NUM, "is", FACTORIAL)