Update examples

set_get_attr_example.py

@@ -1,3 +1,37 @@
+"""
+set_get_attr_example.py
+-----------------------
+
+This module contains a class named `Number` which implements special attribute
+access methods to demonstrate custom attribute setting and getting behaviors
+in a Python class.
+
+Here is a summary of its functionality and methods:
+
+- `__init__(self, number)`: Initializes a new instance with a `number` parameter. 
+- `power(self)`: Squares the current value of the `_number` attribute. It utilizes
+  `self.number` to access the `_number` attribute, which works correctly due to
+  the overridden `__getattribute__` method.
+- `another_func(self)`: Prints a message when invoked.
+- `__str__(self)`: Returns a string representation of the `_number` attribute.
+  
+The class also overrides special methods (`__setattr__`, `__getattribute__`,
+`__getattr__`) to define custom behaviors for setting, getting, and accessing
+non-existent attributes, respectively.
+
+Usage:
+  If run as the main program, an instance of `Number` is created with an initial
+  value of 5. The script then performs various operations to demonstrate the
+  custom attribute access behaviors.
+
+Note:
+  The `__getattribute__` method in the `Number` class is implemented such that if
+  an attribute other than the ones listed in the `options` list is accessed, the
+  `_number` attribute value is returned. This is demonstrated in the script where
+  `number.num` and `number.number` (which are non-existing attributes) are accessed,
+  but the `_number` value is printed instead of raising an AttributeError.
+"""
+
 class Number:
     def __init__(self, number):
         self._number = number
@@ -31,3 +65,11 @@ class Number:
 
     def __getattr__(self, name):
         return self._number
+
+if __name__ == "__main__":
+    number = Number(5)
+    print(number.num)
+    print(number.number)
+    number.power()
+    print(number.num)
+    number.another_func()