Book Image

Modern Python Cookbook - Second Edition

By : Steven F. Lott
Book Image

Modern Python Cookbook - Second Edition

By: Steven F. Lott

Overview of this book

Python is the preferred choice of developers, engineers, data scientists, and hobbyists everywhere. It is a great language that can power your applications and provide great speed, safety, and scalability. It can be used for simple scripting or sophisticated web applications. By exposing Python as a series of simple recipes, this book gives you insight into specific language features in a particular context. Having a tangible context helps make the language or a given standard library feature easier to understand. This book comes with 133 recipes on the latest version of Python 3.8. The recipes will benefit everyone, from beginners just starting out with Python to experts. You'll not only learn Python programming concepts but also how to build complex applications. The recipes will touch upon all necessary Python concepts related to data structures, object oriented programming, functional programming, and statistical programming. You will get acquainted with the nuances of Python syntax and how to effectively take advantage of it. By the end of this Python book, you will be equipped with knowledge of testing, web services, configuration, and application integration tips and tricks. You will be armed with the knowledge of how to create applications with flexible logging, powerful configuration, command-line options, automated unit tests, and good documentation.
Table of Contents (18 chapters)
16
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17
Index

Using cmd to create command-line applications

There are several ways of creating interactive applications. The Using input() and getpass() for user input recipe looked at functions such as input() and getpass.getpass(). The Using argparse to get command-line input recipe showed us how to use argparse to create applications with which a user can interact from the OS command line.

We have a third way to create interactive applications: using the cmd module. This module will prompt the user for input, and then invoke a specific method of the class we provide.

Here's how the interaction will look – we've marked user input like this: "help":

A dice rolling tool. ? for help.
] help
Documented commands (type help <topic>):
========================================
dice  help  reroll  roll
Undocumented commands:
======================
EOF  quit
] help roll
Roll the dice. Use the dice command to set the number of dice.
] help dice
Sets the number...