From 9eb06c36bd4320462ca04fd4872199e4ebd63684 Mon Sep 17 00:00:00 2001
From: d0vgan <dvv81@ukr.net>
Date: Fri, 31 Mar 2023 18:33:15 +0300
Subject: [PATCH] some additional explanations

---
 Finished/Ch_1/bool.py                | 17 +++++++++++++++++
 Finished/Ch_2/docstrings_finished.py |  2 ++
 Finished/Ch_2/keyargs_finished.py    |  1 +
 Finished/Ch_3/listcomp_finished.py   |  2 +-
 Finished/Ch_4/comparison_finished.py |  2 ++
 Finished/Ch_4/compattrs_finished.py  |  5 ++++-
 Finished/Ch_4/enums_finished.py      |  1 +
 Finished/Ch_4/numeric_finished.py    |  3 +++
 Finished/Ch_5/simple_finished.py     |  2 ++
 9 files changed, 33 insertions(+), 2 deletions(-)
 create mode 100644 Finished/Ch_1/bool.py

diff --git a/Finished/Ch_1/bool.py b/Finished/Ch_1/bool.py
new file mode 100644
index 0000000..9c258ee
--- /dev/null
+++ b/Finished/Ch_1/bool.py
@@ -0,0 +1,17 @@
+# demonstrates what is treated as False
+
+if not None:
+    print("None -> False")
+
+if not 0:
+    print("0 -> False")
+
+if not '':
+    print("'' -> False")
+
+if not []:
+    print("[] -> False")
+
+if not {}:
+    print("{} -> False")
+
diff --git a/Finished/Ch_2/docstrings_finished.py b/Finished/Ch_2/docstrings_finished.py
index 570840e..abf110a 100644
--- a/Finished/Ch_2/docstrings_finished.py
+++ b/Finished/Ch_2/docstrings_finished.py
@@ -1,6 +1,8 @@
 # Example file for Advanced Python: Language Features by Joe Marini
 # Demonstrate the use of lambda functions
 
+# Refer to: 
+#   https://peps.python.org/pep-0257
 
 def my_function(arg1, arg2=None):
     """my_function(arg1, arg2=None) --> Doesn't really do anything special.
diff --git a/Finished/Ch_2/keyargs_finished.py b/Finished/Ch_2/keyargs_finished.py
index 694e6b4..e36aa9a 100644
--- a/Finished/Ch_2/keyargs_finished.py
+++ b/Finished/Ch_2/keyargs_finished.py
@@ -3,6 +3,7 @@
 
 
 # use keyword-only arguments to help ensure code clarity
+# the `*` parameter enforces the next parameter to be specified by the keyword
 def my_function(arg1, arg2, *, suppressExceptions=False):
     print(arg1, arg2, suppressExceptions)
 
diff --git a/Finished/Ch_3/listcomp_finished.py b/Finished/Ch_3/listcomp_finished.py
index 68f6595..0b5797a 100644
--- a/Finished/Ch_3/listcomp_finished.py
+++ b/Finished/Ch_3/listcomp_finished.py
@@ -11,7 +11,7 @@
     map(lambda e: e**2, filter(lambda e: e > 4 and e < 16, evens)))
 print(evenSquared)
 
-# Derive a new list of numbers frm a given list
+# Derive a new list of numbers from a given list
 evenSquared = [e ** 2 for e in evens]
 print(evenSquared)
 
diff --git a/Finished/Ch_4/comparison_finished.py b/Finished/Ch_4/comparison_finished.py
index 495876d..71ca673 100644
--- a/Finished/Ch_4/comparison_finished.py
+++ b/Finished/Ch_4/comparison_finished.py
@@ -1,6 +1,8 @@
 # Example file for Advanced Python: Language Features by Joe Marini
 # Use special methods to compare objects to each other
 
+# Refer to:
+#   https://docs.python.org/3/reference/datamodel.html
 
 class Employee():
     def __init__(self, fname, lname, level, years_service):
diff --git a/Finished/Ch_4/compattrs_finished.py b/Finished/Ch_4/compattrs_finished.py
index 3df08a1..8a89850 100644
--- a/Finished/Ch_4/compattrs_finished.py
+++ b/Finished/Ch_4/compattrs_finished.py
@@ -14,6 +14,8 @@ def __getattr__(self, attr):
             return (self.red, self.green, self.blue)
         elif attr == "hexcolor":
             return f"#{self.red:02x}{self.green:02x}{self.blue:02x}"
+        elif attr == "hex": # a method hex()
+            return lambda: f"#{self.red:02x}{self.green:02x}{self.blue:02x}"
         else:
             raise AttributeError(f"{attr} is not a valid attribute")
 
@@ -28,7 +30,7 @@ def __setattr__(self, attr, val):
 
     # use dir to list the available properties
     def __dir__(self):
-        return ("rgbolor", "hexcolor")
+        return ("rgbcolor", "hexcolor")
 
 
 # create an instance of myColor
@@ -36,6 +38,7 @@ def __dir__(self):
 # print the value of a computed attribute
 print(cls1.rgbcolor)
 print(cls1.hexcolor)
+print(cls1.hex())
 
 # set the value of a computed attribute
 cls1.rgbcolor = (125, 200, 86)
diff --git a/Finished/Ch_4/enums_finished.py b/Finished/Ch_4/enums_finished.py
index 7d88958..8ee08e2 100644
--- a/Finished/Ch_4/enums_finished.py
+++ b/Finished/Ch_4/enums_finished.py
@@ -28,3 +28,4 @@ class Fruit(Enum):
 myFruits = {}
 myFruits[Fruit.BANANA] = "Come Mr. Tally-man"
 print(myFruits[Fruit.BANANA])
+print(myFruits)
diff --git a/Finished/Ch_4/numeric_finished.py b/Finished/Ch_4/numeric_finished.py
index 82d4c97..d975e62 100644
--- a/Finished/Ch_4/numeric_finished.py
+++ b/Finished/Ch_4/numeric_finished.py
@@ -1,6 +1,9 @@
 # Example file for Advanced Python: Language Features by Joe Marini
 # give objects number-like behavior
 
+# Refer to:
+#   https://docs.python.org/3/reference/datamodel.html#emulating-numeric-types
+
 
 class Point():
     def __init__(self, x, y):
diff --git a/Finished/Ch_5/simple_finished.py b/Finished/Ch_5/simple_finished.py
index 07b9b9c..83013a7 100644
--- a/Finished/Ch_5/simple_finished.py
+++ b/Finished/Ch_5/simple_finished.py
@@ -1,6 +1,8 @@
 # Example file for Advanced Python: Language Features by Joe Marini
 # Simple pattern matching using literal values
 
+# Note: match-case requires at least Python 3.10
+
 x = 0
 
 # Literal patterns are explicit values like integers, strings, Booleans, etc