There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "Beyond these three packages, the reader will also require the sqlalchemy package, which provides the ORM we will be using throughout the chapter, and psycopg2, which provides postgres database bindings to allow sqlalchemy to connect to postgres."

A block of code is set as follows:

username = request.args.get('username')
email = request.args.get('email')
password = request.args.get('password')
user_record = User(username=username, email=email, password=password)

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

username = request.args.get('username')
email = request.args.get('email')
password = request.args.get('password')
user_record = User(username=username, email=email, password=password)

Any command-line input or output is written as follows:

mkdir ch3 && cd ch3
virtualenv --python=python3 .
source bin/activate
pip install sqlalchemy psycopg2

Bold: Indicates a new term, an important word, or words that you see on screen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "In the web client, access the Apps top menu and select the Update Apps List menu option."