Conventions

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "Use the str.encode(encoding, errors) method, which encodes the string using a registered codec for encoding."

A block of code is set as follows:

[print("hello world")
print "goodbye python2"

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

cdef long long fibonacci_cc(unsigned int n) nogil:
    if n < 2:
        return n
    else:
        return fibonacci_cc(n - 1) + fibonacci_cc(n - 2)

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

$ pip show pip
---
Metadata-Version: 2.0
Name: pip
Version: 7.1.2
Summary: The PyPA recommended tool for installing Python packages.
Home-page: https://pip.pypa.io/
Author: The pip developers
Author-email: python-virtualenv@groups.google.com
License: MIT
Location: /usr/lib/python2.7/site-packages
Requires:

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Clicking the Next button moves you to the next screen."