diff --git a/BoundedInt.py b/BoundedInt.py
new file mode 100644
index 0000000..10ce704
--- /dev/null
+++ b/BoundedInt.py
@@ -0,0 +1,52 @@
+class BoundedInt():
+    def __init__(self, i, min, max):
+        """
+        Create a bounded integer.
+
+        Args:
+            i (int): The initial value of the integer.
+            min (int): The minimum value of the integer.
+            max (int): The maximum value of the integer.
+        """
+        self.i = i
+        if i < min or i > max:
+            raise ValueError(f"{i} is outside the range of [{min}, {max}].")
+        self.min = min
+        self.max = max
+
+    def __int__(self):
+        return self.i
+
+    def __index__(self):
+        return self.i
+
+    def __getattr__(self, name):
+        print(f"DEBUG: {type(name)=}, {name=}")
+        return lambda *args, **kwargs: None
+
+    def __add__(self, y):
+        if isinstance(y, BoundedInt):
+            i = y.i
+        else:
+            i = y
+        if self.i + i > self.max:
+            raise ValueError()
+        else:
+            return BoundedInt(self.i + i, self.min, self.max)
+
+    def __sub__(self, y):
+        if isinstance(y, BoundedInt):
+            i = y.i
+        else:
+            i = y
+        if self.i - i < self.min:
+            raise ValueError()
+        else:
+            return BoundedInt(self.i - i, self.min, self.max)
+
+if __name__ == "__main__":
+    b1 = BoundedInt(1,0,2)
+    b2 = BoundedInt(1,0,2)
+    print(f"{b1.doo}")
+    b3 = b1+b2
+    
\ No newline at end of file
diff --git a/test11.py b/test11.py
index 3e536d2..30ff5f2 100644
--- a/test11.py
+++ b/test11.py
@@ -10,12 +10,6 @@ class TomatoPrice:
     def __radd__(self, operand):
         self.price += operand.price
 
-b'abcdefg'
-str = b.encode('UTF-8')
-for c in str:
-    if ord(c) >= 32 and ord(c) < 127:
-        print(c)
-
 vietnam = TomatoPrice(3.0)
 japan = TomatoPrice(4.0)
 korea = TomatoPrice(5.0)
diff --git a/test13.py b/test13.py
index 13825f6..3c52452 100644
--- a/test13.py
+++ b/test13.py
@@ -28,7 +28,7 @@ class BoundedIntTester:
         Test that addition works for two BoundedInts, and throws an error if the bounds are exceeded.
         """
         bi4 = BoundedInt(1, min = 0, max = 1)
-        bi5 = BoundedInt(2, min = 0, max = 2)
+        bi5 = BoundedInt(2, min = 0, max = -1)
         try:
             bi6 = bi4 - bi5 # 1 - 2 = (-1), which is less than min = 0
             print(f"❌ Test 3 failed!")
diff --git a/test14.py b/test14.py
new file mode 100644
index 0000000..362df35
--- /dev/null
+++ b/test14.py
@@ -0,0 +1,12 @@
+class Test:
+    def __init__(self):
+        pass
+
+    def t1():
+        pass
+
+    def t2():
+        pass
+
+if __name__ == '__main__':
+    t = Test()
\ No newline at end of file
diff --git a/test15.py b/test15.py
new file mode 100644
index 0000000..a5135fc
--- /dev/null
+++ b/test15.py
@@ -0,0 +1,21 @@
+class NotAdder:
+    def __init__(self):
+        self.i = 0
+    def __add__(self, other):
+        return NotImplemented
+
+class Adder:
+    def __init__(self):
+        self.i = 1
+    def __add__(self, other: NotAdder):
+        return self.i + other.i
+    def __radd__(self, other: NotAdder):
+        return self.i + other.i
+
+if __name__ == '__main__':
+    na = NotAdder()
+    a = Adder()
+    na + a
+
+# if a + na => NotImplemented then
+# na.__radd__(a)
\ No newline at end of file
diff --git a/test16.py b/test16.py
new file mode 100644
index 0000000..db57212
--- /dev/null
+++ b/test16.py
@@ -0,0 +1,49 @@
+class BoundedInt():
+    def __init__(self, i, min, max):
+        self.i = i
+        self.min = min
+        self.max = max
+
+    def __index__(self):
+        return self.i
+
+    def __add__(self, other):
+        if isinstance(other, BoundedInt):
+            result = self.i + other.i
+        elif isinstance(other, str):
+            score = sentiment(other)
+            result = self.i + score
+        else:
+            result = self.i + other
+        if result > self.max:
+            raise ValueError("Result exceeds max value")
+        return BoundedInt(result, self.min, self.max)
+
+    def __sub__(self, other):
+        if isinstance(other, BoundedInt):
+            result = self.i - other.i
+        elif isinstance(other, str):
+            score = sentiment(other)
+            result = self.i - score
+        else:
+            result = self.i - other
+        if result < self.min:
+            raise ValueError("Result exceeds min value")
+        return BoundedInt(result, self.min, self.max)
+
+
+def sentiment(emoji):
+    sentiment_scores = {
+        "😀": 8.9,
+        "😢": -6.2,
+        "😡": -9.5,
+        "😍": 9.8,
+    }
+    return sentiment_scores.get(emoji, 0.0)
+
+if __name__ == '__main__':
+    b = BoundedInt(3, min = 0, max = 8)
+    b -= "😢"
+
+    #a = [1,2,3,4,5,6,7,8,9,10]
+    #print(f"{a[b]=}")
\ No newline at end of file
diff --git a/test17.py b/test17.py
new file mode 100644
index 0000000..2ce71c5
--- /dev/null
+++ b/test17.py
@@ -0,0 +1,46 @@
+class Test:
+    a = [1,2,3,4,5]
+
+    a1 = 1
+    def __init__(self) -> None:
+        pass
+
+    def sentiment(self):
+        pass
+
+    def __getattr__(self, str):
+        print(f"DEBUG: attempt to access attr {str}")
+        if int(str[1]) > 0 and int(str[1]) < 6:
+            return self.a[int(str[1])]
+
+    def c():
+        print(f"DEBUG: {c.__self__=}")
+        
+    def i(self):
+        pass
+        #print(f"DEBUG: {i.__self__=}")
+
+class ChildTest(Test):
+    pass
+
+if __name__ == '__main__':
+    def whoami(who):
+        if isinstance(Test.c(), Test):
+            print("It's a Test!")
+        if isinstance(ChildTest.c(), ChildTest):
+            print("It's a ChildTest!")
+
+    test = Test()
+    childtest = ChildTest()
+    test.sentiment
+    whoami(test)
+    whoami(childtest)
+    print(f"{test.a1}")
+    print(f"{hasattr(test, 'sentiment')}")
+
+    print(f"{test.c=}")
+    print(f"{childtest.c=}")
+    test.i()
+
+    #print(test['1099'][2019][3])
+    #print(test.1099_2019_3)
\ No newline at end of file
diff --git a/test18.py b/test18.py
new file mode 100644
index 0000000..332d6b0
--- /dev/null
+++ b/test18.py
@@ -0,0 +1,26 @@
+class C:
+    @classmethod
+    def class_method(cls):
+        print("Called class_method with cls:", cls)
+
+    def instance_method(self):
+        print("Called instance_method with self:", self)
+
+    @staticmethod
+    def static_method():
+        print("Called static_method")
+
+# Accessing class attributes
+class_method_obj = C.__dict__["class_method"]
+instance_method_obj = C.__dict__["instance_method"]
+static_method_obj = C.__dict__["static_method"]
+
+# Calling the methods directly (without transformation)
+class_method_obj.__func__(C)  # Output: Called class_method with cls: <class '__main__.C'>
+instance_method_obj.__func__(1)  # Output: Called instance_method with self: <__main__.C object at 0x7f8d7c1e4d90>
+static_method_obj.__func__()  # Output: Called static_method
+
+# Accessing the methods through class attribute reference (with transformation)
+C.class_method()  # Output: Called class_method with cls: <class '__main__.C'>
+C.instance_method(1)  # Raises TypeError: instance_method() missing 1 required positional argument: 'self'
+C.static_method()  # Output: Called static_method
\ No newline at end of file
diff --git a/test19.py b/test19.py
new file mode 100644
index 0000000..699a96d
--- /dev/null
+++ b/test19.py
@@ -0,0 +1,14 @@
+class Hotdog:
+    count: float = 0
+    def __init__(self) -> None:
+        Hotdog.count += 1
+
+    @staticmethod
+    def get_count() -> int:
+        return Hotdog.count
+
+if __name__ == '__main__':
+    h1 = Hotdog()
+    print(Hotdog.get_count())
+    h2 = Hotdog()
+    print(Hotdog.get_count())
\ No newline at end of file
diff --git a/test20.py b/test20.py
new file mode 100644
index 0000000..0033851
--- /dev/null
+++ b/test20.py
@@ -0,0 +1,33 @@
+class Menu:
+    hotdog = 10
+    hamburger = 10
+
+    def __init__(self) -> None:
+        self.hotdog = 10
+        self.hamburger = 10
+
+
+class SlotsMenu:
+    __slots__ = ('hotdog', 'hamburger', 'cheeseburger')
+
+    def __init__(self) -> None:
+        self.hotdog = 10
+        self.hamburger = 10
+
+    def __get__(self, instance):
+        print(f"DEBUG: looked up {instance}")
+
+if __name__ == '__main__':
+    menu = Menu()
+
+    print(f"cost of hamburger = {menu.hamburger}")
+    menu.__dict__['hamburger'] = 1
+    print(f"new cost of hamburger = {menu.hamburger}")
+
+    slotsmenu = SlotsMenu()
+
+    print(f"cost of hamburger = {slotsmenu.hamburger}")
+    slotsmenu.cheeseburger = 1
+    print(f"cost of cheeseburger: {slotsmenu.cheeseburger=}")
+    #slotsmenu.__dict__['hamburger'] = 1
+    print(f"new cost of hamburger = {slotsmenu.hamburger}")
diff --git a/test21.py b/test21.py
new file mode 100644
index 0000000..0be4ad6
--- /dev/null
+++ b/test21.py
@@ -0,0 +1,17 @@
+from random import random
+class EvilDescriptor:
+    i: int
+
+    def __init__(self, i) -> None:
+        self.i = i
+
+    def __set__(self, instance, i: int):
+        self.instance = i + (random()*10)-5
+
+    def __index__(self):
+        return int(self.i)
+
+if __name__ == '__main__':
+    evil = EvilDescriptor(3)
+    evil.i = 5
+    print(f"{int(evil)=}")
\ No newline at end of file
diff --git a/test22.py b/test22.py
new file mode 100644
index 0000000..4826c2a
--- /dev/null
+++ b/test22.py
@@ -0,0 +1,17 @@
+class Vault2:
+    def __init__(self):
+        self._treasure = "gold"
+        self._original_dict = dict(self.__dict__)
+
+    def __setattr__(self, name, value):
+        if name != "_treasure" and name in self.__dict__ and self._original_dict.get(name) != value:
+            print("attribute deleted!")
+        self.__dict__[name] = value
+
+    @property
+    def treasure(self):
+        if self.__dict__ != self._original_dict:
+            print("attribute deleted!")
+        return self._treasure
+v = Vault2()
+print(v.treasure)
diff --git a/test23.py b/test23.py
new file mode 100644
index 0000000..3cc69c3
--- /dev/null
+++ b/test23.py
@@ -0,0 +1,23 @@
+class Vault:
+    def __init__(self):
+        self._treasure = 'gold'
+        self._original_attrs = self.__dict__.copy()
+
+    @property
+    def treasure(self):
+        if self.__dict__ != self._original_attrs:
+            print('Attribute deleted!')
+        return self._treasure
+    def stuff(self):
+        ...
+
+    def __setattr__(self, key, value):
+        self.__dict__[key] = value
+        if key != '_original_attrs' and hasattr(self, '_original_attrs') and self.__dict__ != self._original_attrs:
+            print('Attribute deleted!')
+
+    def __call__(self, *args):
+        print(f"attempt to call {args}")
+
+v = Vault()
+v(1,2,3)
\ No newline at end of file