Updating code to reflect comments in PR

python-sqlite-sqlalchemy/README.md

-# Python / Sqlite /SqlAlchemy article
+# Python / SQLite /SqlAlchemy article
 
 This repository contains the content and example code
-for the python / sqlite / sqlaclchemy article I'm writing
+for the Python / SQLite / SqlAclchemy article I'm writing
 for Real Python.
 
 This project was built using Python 3.8.0
@@ -11,7 +11,7 @@ This project was built using Python 3.8.0
 I use the `pyenv` tool to install Python versions on my Mac. I find it a very useful tool, and the instructions that follow use it, and are based on having Python version 3.8.0 installed using the following command:
 
 ```shell
-pyenv install 3.8.0
+$ pyenv install 3.8.0
 ```
 
 ## Installing The Project

python-sqlite-sqlalchemy/project/examples/example_1/main.py

@@ -57,21 +57,16 @@ def add_new_book(data, author_name, book_title, publisher_name):
     """Adds a new book to the system"""
 
     # Does the book exist?
-    if book_title in data["title"].values:
-        raise ValueError("Book exists", book_title)
-
-    # Does the author exist?
     first_name, _, last_name = author_name.partition(" ")
-    if not any(
-        data["first_name"].str.contains(first_name)
-        & data["last_name"].str.contains(last_name)
+    if any(
+        (data.first_name == first_name)
+        & (data.last_name == last_name)
+        & (data.title == book_title)
+        & (data.publisher == publisher_name)
     ):
-        raise ValueError("No author found", author_name)
-
-    # Does the publisher exist?
-    if publisher_name not in data["publisher"].values:
-        raise ValueError("No publisher found", publisher_name)
-
+        raise ValueError(
+            "New item exists", author_name, book_title, publisher_name
+        )
     # Add the new book
     return data.append(
         {

python-sqlite-sqlalchemy/project/examples/example_2/main.py

 """
-This program gathers information from the temp_data.csv file about temperature
+This program gathers information from the author_book_publisher.db 
+SQLite database file
 """
 
-from uuid import uuid4
-
-from pkg_resources import resource_filename
+from importlib import resources
 from sqlalchemy import and_, create_engine
 from sqlalchemy.orm import sessionmaker
 from sqlalchemy.sql import asc, desc, func
@@ -93,9 +92,10 @@ def add_new_book(session, author_name, book_title, publisher_name):
         .filter(Publisher.name == publisher_name)
         .one_or_none()
     )
-    # Does book not exist, and the author or publisher also not existexist?
-    if book is not None and not (author is None or publisher is None):
-        raise Exception(
+    # Does book, author and publisher already exist?
+    print(book)
+    if book is not None and author is not None and publisher is not None:
+        raise ValueError(
             "New item exists", author_name, book_title, publisher_name
         )
     # Create the book
@@ -129,14 +129,12 @@ def output_author_hierarchy(authors):
         )
         for book in author.books:
             authors_tree.create_node(
-                f"{book.title}",
-                f"{book.title}",
+                book.title,
+                book.title,
                 parent=f"{author.first_name} {author.last_name}",
             )
             for publisher in book.publishers:
-                authors_tree.create_node(
-                    f"{publisher.name}", uuid4(), parent=f"{book.title}"
-                )
+                authors_tree.create_node(publisher.name, parent=book.title)
     # Output the hierarchical authors data
     authors_tree.show()
 
@@ -145,16 +143,16 @@ def main():
     """Main entry point of program"""
 
     # Connect to the database using SqlAlchemy
-    sqlite_filepath = resource_filename(
+    with resources.path(
         "project.data", "author_book_publisher.db"
-    )
-    engine = create_engine(f"sqlite:///{sqlite_filepath}")
+    ) as sqlite_filepath:
+        engine = create_engine(f"sqlite:///{sqlite_filepath}")
     Session = sessionmaker()
     Session.configure(bind=engine)
     session = Session()
 
     # Get the total number of books printed by each publisher
-    books_by_publisher = get_books_by_publishers(session)
+    books_by_publisher = get_books_by_publishers(session, ascending=False)
     for row in books_by_publisher:
         print(f"Publisher: {row.name}, total books: {row.total_books}")
     print()