This book will give you an overview of in-depth knowledge of blockchain and Bitcoin. You need not have any prior knowledge before exploring this book. You will get well versed in how exactly the blockchain technology is implemented in today's world, and how it enables permanent, transparent, and secure data storage. This is a perfect entry point to decentralized digital databases. By the end of this book, you will know all the basic concepts and challenges of the blockchain technology, how this technology helps secure your cryptocurrency, the concepts around decentralized digital money, and also blockchain and Bitcoin security.

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: "This template creates a form whose superclass is QWidget rather than QDialog."

A block of code is set as follows:

import sys
from PyQt5.QtWidgets import QDialog, QApplication
from demoSignalSlot1 import *
class MyForm(QDialog):
    def __init__(self):
        super().__init__()
        self.ui = Ui_Dialog()
        self.ui.setupUi(self)
        self.show()
if __name__=="__main__":
    app = QApplication(sys.argv)
    w = MyForm()
    w.show()
    sys.exit(app.exec_())

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

[default]
exten => s,1,Dial(Zap/1|30)
exten => s,2,Voicemail(u100)
exten => s,102,Voicemail(b100)
exten => i,1,Voicemail(s0)

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

C:\Pythonbook\PyQt5>pyuic5 demoLineEdit.ui -o demoLineEdit.py

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "The amount the slider handle moves can be specified via the pageStep property."