Michael Driscoll - Python 201: Intermediate Python

Welcome to Python 201! This book is a sequel to my first book, Python101. I wrote this book to help take you to the next level in yourprogramming journey. It will also demonstrate to you some of the manyways you can use Python in your day-to-day work. I will be coveringintermediate and some advanced level material in this book. This book isusing Python 3 in all of its examples. Some of the topics covered willonly work in Python 3 as some of the modules covered contain updatesthat were not back-ported to Python 2. Also note that this book willfollow in the footsteps of my first work in that I wont be covering thetopics in minute detail, but just enough to allow you to start usingthese building blocks yourself.

Python 201 will be split into four parts:

• Part one will cover intermediate modules
• Part two will be on a variety of topics, such as unicode,generators and iterators
• Part three will cover web related tasks with Python (but notweb frameworks)
• Part four is going to cover testing code

Let me spend a few moments explaining what each part has to offer. Inpart one, we will cover the following intermediate modules and topics:

• argparse (Parsing command line arguments)
• collections (Replacements for Pythons standard containers, suchas tuple, list and dict)
• contextlib (Context Managers)
• functools (Partials, function overloading, etc)
• importing and importlib
• iterators and generators
• itertools (Creating your own iterators)
• Regular Expressions
• Type Hinting

In Part two, we will be learning what generators and iterators are aswell as how they work. Well also be looking at some of Pythons specialfunctions, like map and filter. There will be a section onUnicode, encoding and decoding strings, benchmarking and more in thissection.

Part three will cover working with websites in Python. Well look at howto browse a website with Python and scrape some data. We will work withvarious Python APIs to access major websites. We will use Python tocreate a client and a server. Finally well play around with PythonsFTP capabilities.

Part four is all about testing your code. We will look at Pythonsdoctest, unittest and mock modules. Well also learn about some 3rdparty packages that you can use for testing, such as tox, nose andpytest.

Please note that the chapters and sections may not all be the samelength. While every topic will be covered well, not every topic willrequire the same page count.

You may be wondering about who I am and why I might be knowledgeableenough about Python to write about it, so I thought Id give you alittle information about myself. I started programming in Python in theSpring of 2006 for a job. My first assignment was to port Windows loginscripts from Kixtart to Python. My second project was to port VBA code(basically a GUI on top of Microsoft Office products) to Python, whichis how I first got started in wxPython. Ive been using Python eversince, doing a variation of backend programming and desktop front enduser interfaces.

I realized that one way for me to remember how to do certain things inPython was to write about them and thats how my Python blog came about:http://www.blog.pythonlibrary.org/. As I wrote, I would receivefeedback from my readers and I ended up expanding the blog to includetips, tutorials, Python news, and Python book reviews. I work regularlywith Packt Publishing as a technical reviewer, which means that I get totry to check for errors in the books before theyre published. I alsohave written for the Developer Zone (DZone) and i-programmer websites aswell as the Python Software Foundation. In November 2013, DZonepublished The Essential Core Python Cheat Sheet that I co-authored.I have also self-published Python 101, which came out in June 2014.

As with most technical books, this one includes a few conventions thatyou need to be aware of. New topics and terminology will be in bold.You will also see some examples that look like the following:

The >>> is a Python prompt symbol. You will see this in thePython interpreter and in IDLE. Other code examples will beshown in a similar manner, but without the >>>.

You will need a working Python 3 installation. Most Linux and Macmachines come with Python already installed, however they might not havePython 3 as their default. If you happen to find yourself withoutPython, you can go download a copy fromhttp://python.org/download/. There areup-to-date installation instructions on their website, so I wontinclude any installation instructions in this book. Any additionalrequirements will be explained later on in the book.

I welcome feedback about my writings. If youd like to let me know whatyou thought of the book, you can send comments to the following address:

I try my best not to publish errors in my writings, but it happens fromtime to time. If you happen to see an error in this book, feel free tolet me know by emailing me at the following:

Now lets get started!