Fixed syntax error in example 1 main.py and the add_new_book problem in example 2

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

@@ -30,9 +30,10 @@ def get_books_by_publisher(data, ascending=True):
     Returns:
         The sorted data as a pandas series
     """
-    return data.groupby("publisher")
-    .size()
-    .sort_values(ascending=ascending)
+    return (data.groupby("publisher")
+        .size()
+        .sort_values(ascending=ascending)
+    )
 
 
 def get_authors_by_publisher(data, ascending=True):

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

@@ -94,9 +94,8 @@ def add_new_book(session, author_name, book_title, publisher_name):
     )
     # Does book, author and publisher already exist?
     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
-        )
+        return
+
     # Create the book
     book = Book(title=book_title)