Additional comments in "Start" and fix of incorrect values in "Finished"

Finished/Ch 4/challenge.py

@@ -33,10 +33,10 @@ def __lt__(self, other):
 
 # ~~~~~~~~~ TEST CODE ~~~~~~~~~
 stocks = [
-    Stock("MSFT", 342.0, "Microsoft Corp"),
-    Stock("GOOG", 135.0, "Google Inc"),
-    Stock("META", 275.0, "Meta Platforms Inc"),
-    Stock("AMZN", 120.0, "Amazon Inc")
+    Stock(342.0, "MSFT", "Microsoft Corp"),
+    Stock(135.0, "GOOG", "Google Inc"),
+    Stock(275.0, "META", "Meta Platforms Inc"),
+    Stock(120.0, "AMZN", "Amazon Inc")
 ]
 
 bonds = [

Start/Ch 2/abstract_start.py

@@ -1,15 +1,17 @@
 # Python Object Oriented Programming by Joe Marini course example
 # Using Abstract Base Classes to enforce class constraints
 
+#TODO: Import "ABC"(abstract base classes) and abstractmethod from abc
 
+#TODO: Inherit from ABC indicates that this is an abstract base class
 class GraphicShape:
     def __init__(self):
         super().__init__()
-
+    # declaring a method as abstract requires a subclass to implement it
     def calcArea(self):
         pass
 
-
+#TODO: Create specific versions of "calcArea" for different shapes
 class Circle(GraphicShape):
     def __init__(self, radius):
         self.radius = radius

Start/Ch 2/composition_start.py

@@ -1,7 +1,7 @@
 # Python Object Oriented Programming by Joe Marini course example
 # Using composition to build complex objects
 
-
+#TODO: Arrange the composition of the Book class to operate on subclasses
 class Book:
     def __init__(self, title, price, authorfname, authorlname):
         self.title = title
@@ -15,6 +15,13 @@ def __init__(self, title, price, authorfname, authorlname):
     def addchapter(self, name, pages):
         self.chapters.append((name, pages))
 
+     #TODO: Method for counting the total number of pages from all chapters
+
+#TODO: Create classes "Chapter"(with attributes "name" and "pages")
+# and "Author" with ("fname" and "lname") and a method __str__ returning author details
+
+
+#TODO: Create an author object and add it to the book
 
 b1 = Book("War and Peace", 39.0, "Leo", "Tolstoy")
 

Start/Ch 2/inheritance_start.py

@@ -1,15 +1,20 @@
 # Python Object Oriented Programming by Joe Marini course example
 # Understanding class inheritance
 
+#TODO: Create a class "Publication" with attributes "title" and "price"
 
+#TODO: Create a class "Perdiodicaly" that inherits from "Publication"
+# and additionally has attributes "period" and "publisher"
+
+#TODO: Allow the "Book" class to inherit attributes from Publication
 class Book:
     def __init__(self, title, author, pages, price):
         self.title = title
         self.price = price
         self.author = author
         self.pages = pages
 
-
+#TODO: The Magazine and Newspaper classes can inherit all atributes from "Perdiodicaly"
 class Magazine:
     def __init__(self, title, publisher, price, period):
         self.title = title

Start/Ch 2/interface_start.py

@@ -12,13 +12,16 @@ def __init__(self):
     def calcArea(self):
         pass
 
+# TODO: Add abstract class "JSONify" with abstract method "toJSON"
 
 class Circle(GraphicShape):
     def __init__(self, radius):
         self.radius = radius
 
     def calcArea(self):
         return 3.14 * (self.radius ** 2)
+
+    # TODO: Override "toJSON" method to return a JSON representation of "calcArea"
 
 
 c = Circle(10)

Start/Ch 2/multiple_start.py

@@ -1,7 +1,7 @@
 # Python Object Oriented Programming by Joe Marini course example
 # Understanding multiple inheritance
 
-
+#TODO: For A and B class create an attribute "name" that will take different values
 class A:
     def __init__(self):
         super().__init__()
@@ -17,6 +17,7 @@ def __init__(self):
 class C(A, B):
     def __init__(self):
         super().__init__()
-
+    #TODO: Create the method "showprops" returning the attributes it owns
 
 c = C()
+#TODO: You can use showprops() and also call "Class.__mro__" to find out all the parent classes

Start/Ch 4/dataclass_start.py

@@ -1,6 +1,7 @@
 # Python Object Oriented Programming by Joe Marini course example
 # Using data classes to represent data objects
 
+#TODO: Import dataclasses from dataclass and apply decorator
 
 class Book:
     def __init__(self, title, author, pages, price):

Start/Ch 4/datadefault_start.py

@@ -1,8 +1,12 @@
 # Python Object Oriented Programming by Joe Marini course example
 # implementing default values in data classes
 
+# TODO: Import "field" function from dataclasses
 from dataclasses import dataclass
 
+# TODO: Define a function that returns a random number between 20-40.
+# Don't forget to import the necessary module
+
 
 @dataclass
 class Book:
@@ -11,3 +15,4 @@ class Book:
     author: str
     pages: int
     price: float
+    # TODO: Use the field function to get default price as random number

Start/Ch 4/immutable_start.py

@@ -10,7 +10,7 @@ class ImmutableClass:
     value2: int = 0
 
 
-obj = ImmutableClass()
+obj = ImmutableClass() # You can set the values of frozen class only with initialization
 print(obj.value1)
 
 # TODO: attempting to change the value of an immutable class throws an exception