From 9ea144f3bdc8260c43715897103cf2177842e3db Mon Sep 17 00:00:00 2001
From: Utsav Akash Naskar <utsavakash123@gmail.com>
Date: Tue, 28 Jul 2020 13:29:44 +0530
Subject: [PATCH] Added Python Program to Check Perfect Number (#2244)

* Added Python Program to Check Perfet Number

* CodeSpell Error Fix - 1

* Build Error Fix - 1

* Made suggested changes

* Use generator expression

Co-authored-by: Christian Clauss <cclauss@me.com>
---
 maths/perfect_number.py | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 maths/perfect_number.py

diff --git a/maths/perfect_number.py b/maths/perfect_number.py
new file mode 100644
index 000000000..3de742399
--- /dev/null
+++ b/maths/perfect_number.py
@@ -0,0 +1,34 @@
+"""
+== Perfect Number ==
+In number theory, a perfect number is a positive integer that is equal to the sum of
+its positive divisors, excluding the number itself.
+For example: 6 ==> divisors[1, 2, 3, 6]
+    Excluding 6, the sum(divisors) is 1 + 2 + 3 = 6
+    So, 6 is a Perfect Number
+
+Other examples of Perfect Numbers: 28, 486, ...
+
+https://en.wikipedia.org/wiki/Perfect_number
+"""
+
+
+def perfect(number: int) -> bool:
+    """
+    >>> perfect(27)
+    False
+    >>> perfect(28)
+    True
+    >>> perfect(29)
+    False
+
+    Start from 1 because dividing by 0 will raise ZeroDivisionError.
+    A number at most can be divisible by the half of the number except the number
+    itself.  For example, 6 is at most can be divisible by 3 except by 6 itself.
+    """
+    return sum(i for i in range(1, ((number // 2) + 1)) if number % i == 0) == number
+
+
+if __name__ == "__main__":
+    print("Program to check whether a number is a Perfect number or not.......")
+    number = int(input("Enter number: ").strip())
+    print(f"{number} is {'' if perfect(number) else 'not '} a Perfect Number.")