Conventions

In this book, you will find a number of styles of text 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: "Storm configurations can be done using storm.yaml, which is present in the conf folder".

A block of code is set as follows:

import nltk.corpus

from petrel import storm
from petrel.emitter import BasicBolt

class SplitSentenceBolt(BasicBolt):
    def __init__(self):
        super(SplitSentenceBolt, self).__init__(script=__file__)
        self.stop = set(nltk.corpus.stopwords.words('english'))
        self.stop.update(['http', 'https', 'rt'])

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

import logging
from collections import defaultdict

from petrel import storm
from petrel.emitter import BasicBolt

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

tail -f petrel24748_totalrankings.log

New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "Finally, click on Create your Twitter application".

Note

Warnings or important notes appear in a box like this.

Tip

Tips and tricks appear like this.