Font Conventions

This book uses the following typographical conventions:

Italic

For email addresses, filenames, URLs, for emphasizing new terms when first introduced, and for some comments within code sections

Constant width

Shows the contents of files or the output from commands and to designate modules, methods, statements, and commands

Constant width bold

In code sections to show commands or text that would be typed

Constant width italic

Shows replaceables in code sections

<Constant width>

Represents syntactic units that you replace with real code

Indicates a tip, suggestion, or general note relating to the nearby text.

Indicates a warning or caution relating to the nearby text.

In our examples, the % character at the start of a system command line stands for the system's prompt, whatever that may be on your machine (e.g., C:\Python22> in a DOS window). Don't type the % character yourself! Similarly, in interpreter interaction listings, do not type the >>> and . . . characters shown at the start of lines—these are prompts that Python displays. Type just the text after these prompts. To help you remember this, user inputs are shown in bold font in this book. Also, you normally don't need to type text that starts with a # in listings; as we'll explain later, these are comments, not executable code.