Daniel Arbuckle's mastering Python: build powerful Python applications

266 Pages·2017·8.244 MB·English

by  Arbuckle, Daniel

Daniel Arbuckle's Mastering
Python
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Daniel Arbuckle
BIRMINGHAM - MUMBAI
Daniel Arbuckle's Mastering Python
Copyright © 2017 Packt Publishing
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First published: June 2017
Production reference: 1300617
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ISBN 978-1-78728-369-5
Credits
Author Copy Editor
Daniel Arbuckle Tom Jacob
Acquisition Editor Project Coordinator
Ben Renow-Clarke Suzanne Coutinho
Content Development Editor Proofreader
Monika Sangwan Safis Editing
Technical Editor Indexer
Devesh Chugh Aishwarya Gangawane
Graphics Production Coordinator
Kirk D'Penha Arvindkumar Gupta
About the Author
Daniel Arbuckle gained his PhD in Computer Science from the University of Southern
California. He has published numerous papers along with several books and video courses,
and he is both a teacher of computer science and a professional programmer.
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Table of Contents
Preface
1
Chapter 1: Python Primer
6
Python basic syntax and block structure 6
Basic building blocks 8
Functions 8
Variables 10
Expressions 11
Classes 12
Flow control statements 13
Indentation 14
Python's built-in data structures and comprehensions 15
Dictionaries 15
List 16
Tuple 17
Set 18
Comprehension 19
First-class functions and classes 20
The defaultdict class 22
Attributes 23
The standard library 24
Different types of packages 24
What's new in modern Python 26
The changes in the syntactic 27
Changes in packages 28
Other changes in Python packages 29
Summary 30
Chapter 2: Setting Up
31
Downloading and installing Python 31
Choosing a suitable version 32
Installing Python 32
Using the command line and the interactive shell 34
Opening a command-line window 34
Python interactive shell 35
Installing packages with pip 38
The pip tool for packages 38
Managing installed packages 39
Finding packages in the Python Package Index 42
Using keywords 42
Using Package Index 42
Searching the Package Index with pip 43
Legalities and licenses of the Python Package Index 43
Summary 44
Chapter 3: Making a Package
45
Creating an empty package 45
Turning a regular folder into a package 46
Importing all package modules 47
Adding modules to the package 49
Module loading with namespace packages 50
The Package structure and interface 51
Accessing code from other modules 53
Importing a cyclic dependency 54
Resolving attribute errors raised due to cyclic dependencies 55
Adding static data files to the package 56
Summary 57
Chapter 4: Basic Best Practices
58
PEP 8 and writing readable code 59
PEP 8 — guidelines for Python code 59
Code indentation 60
Formatting recommendations 61
Naming conventions 63
Using version control 63
Initializing Git 64
Committing the changes in Git 64
Undoing the changes 65
Branches 66
Merging codes 68
The mergetool command 69
The pull command 70
Using venv to create a stable and isolated work area 70
Creating a virtual environment 71
Activating a virtual environment 71
pip in virtual environments 72
Getting the most out of docstrings 73
PEP 257 and docutils 73
[ ii ]
Sphinx 74
Turning docstrings into HTML 76
Using doctest to test documentation examples 80
Testing examples using doctest 81
What it means when a code example fails 82
Summary 82
Chapter 5: Making a Command-Line Utility
83
Making a package executable via Python -m 84
Pipeline program 85
Handling command-line arguments with argparse 87
Creating an ArgumentParser object 87
Setting the name of argument 88
nargs 90
Python tools to interact with the user 92
Python's built-in functions - print and input 92
The getpass package 93
The pprint package 93
The cmd class 94
The Pipeline user interface 96
Executing other programs with subprocess 98
Subprocess and its variants 98
Using the Popen subprocess 101
The PIPE constant 101
The wait method 102
Finishing up our code example 103
Setting up a shell script or batch file to launch the program 104
Creating launches for our program 104
Summary 105
Chapter 6: Parallel Processing
106
Using the concurrent.futures package 106
The concurrent.futures module 108
Calling ProcessPoolExecutor 109
Using the map method 111
Using the submit method 111
The done and result methods 113
The wait and as_completed functions 115
The add done callback function 116
The cancel method 116
Using the multiprocessing packages 117
Process class in the multiprocessing module 118
Queues 119
[ iii ]