Course 1906 Advanced Python: Best Practices and Design Patterns by Michael Woinoski Technical Editor: Alexander Lapajne 1906/CN/C.1/911/B.1 Copyright © LEARNING TREE INTERNATIONAL, INC. All rights reserved. All trademarked product and company names are the property of their respective trademark holders. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, or translated into any language, without the prior written permission of the publisher. Copying software used in this course is prohibited without the express permission of Learning Tree International, Inc. Making unauthorized copies of such software violates federal copyright law, which includes both civil and criminal penalties. © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Access Your Do Now Course Materials 1. Log in to your My Learning Tree Account 2. Find your upcoming course, and click 3. Under Course Materials, click the links to open your course files 4. Right-click or use the icons to download and save the files to an easily accessible location © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Welcome-1 Access Your Do Now Course Materials 5. Begin highlighting and adding comments to your downloaded PDF (experiences will differ based on reader/viewer used) Take your notes with you! • Add your downloaded course materials to any cloud-based storage service (Google Drive, Dropbox, etc.) • E-mail the materials as an attachment • Save the course materials to a USB drive © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Welcome-2 Welcome! Do Now ► Meet your Instructor and Classmates • Share your: ◦ Name ◦ Background / current position ◦ Course expectations © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Welcome-3 Course Schedule ► Each day, the course will follow this schedule: • Start Class • Morning Break • Lunch • Resume Class • Afternoon Break(s) • End Time • Last-Day Course Exam ► Course logistics: • Wi-Fi information available at reception • Facilities • Local amenities • Emergency measures If we can help improve your experience, please let us know! © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Welcome-4 Introduction and Overview Course Objectives ► Employ best practices and design patterns to build Python applications that are reliable, efficient, and testable ► Exploit Python’s OOP features for stable, maintainable code ► Automate unit testing with the Unittest, Pytest, and Mock modules ► Measure and improve performance of Python applications using profiling tools, code optimization techniques, and PyPy ► Install and distribute Python programs and modules using standard Python tools, including Pip and Python Packaging Index (PyPI) OOP = object-oriented programming © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Intro-2 Course Objectives ► Create and manage concurrent threads of control ► Generate and consume REST web service requests and responses REST = representational state transfer © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Intro-3 Course Contents Introduction and Overview Chapter 1 Object-Oriented Programming in Python Chapter 2 Design Patterns in Python Chapter 3 Unit Testing and Mocking Chapter 4 Error Detection and Debugging Techniques Chapter 5 Measuring and Improving Performance Chapter 6 Design Patterns II Chapter 7 Installing and Distributing Modules Chapter 8 Concurrent Execution Chapter 9 Interfacing With REST Web Services and Clients Chapter 10 Course Summary Next Steps © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Intro-4 Course Contents Appendix A Extending Python Appendix B Advanced Python Features © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Intro-5 Goals of the Course ► Gain experience implementing design patterns in Python • Experienced programmers may use same design patterns in all languages ► You’ll be able to apply Python best practices in your code • Applying best practices results in better code ► You’ll be able to read and understand complex Python code • We’ll look at some Pythonic “magic” so you will understand how it works © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Intro-6 Expected Background ► Real-world experience in Python is expected to the level of Course 1905, Introduction to Python Training • Familiarity with the core Python language features ◦ Defining modules and packages ◦ Built-in data types, decisions (if/elif/else), looping (while, for) ◦ Defining and calling functions ◦ Exception handling: try/except/finally, raise ◦ Object-oriented programming in Python © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Intro-7 Our Classroom Environment ► Software installed on your workstations: Python 2, Python 3 Python interpreters PyCharm, IDLE Python IDEs (PyCharm for exercises) Notepad++, VS Code, Text editors Atom, vim MySQL Database for examples and exercises WSL Ubuntu Linux Windows Subsystem for Linux with Ubuntu bash line editing and command history for Windows Clink command prompt © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Intro-8 Programming Environment ► You’ll complete hands-on exercises in a Windows environment • Most examples and exercises will run unchanged on UNIX, Linux, and Mac ► Examples and exercises are compatible with Python 3 • Some Python 3 changes are not backward compatible with Python 2 • Lecture material highlights differences between Python versions • Python 3 syntax is identified this symbol: ► Exercise instructions are written for PyCharm IDE • For interactive use, PyCharm includes a Python console © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Intro-9 Hands-On Exercises ► Exercises appear throughout the course • To reinforce your learning ► All exercises have bonus sections to complete if you have more time • You won’t have time to finish them all in class! ► Hints are available for all of the coding exercises • Open a web browser and visit the course home page ► All exercises, solutions, and course examples are available for download • Visit My Learning Tree • Navigate to My Courses/Transcripts • Find Python Best Practices and Design Patterns and click View button • Under Course Notes and Exercise Manuals, click the link for Download your CD1 ► You will do the hands-on exercises on a remote Virtual Machine (VM) © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Intro-10 Accessing Your Virtual Machine (VM) Do Now ► Perform these steps to access your VM: 1. Open Chrome and navigate to https://www.learningtree.com 2. Log in to My Learning Tree ◦ Your instructor will give you a temporary password if you need it 3. Click Course History > Course Enrollments > Advanced Python Best Practices and Design Patterns > Details 4. Click Access My Virtual Machine 5. Click the RDP button (above the thumbnail of the desktop) 6. Click Download RDP 7. Click the downloaded file in the Chrome status bar 8. Click Connect 9. Click Yes in the warning dialog about the remote computer’s identity 10.Enter your credentials ◦ Username: user ◦ Password: pw 11.Right-click the desktop > Screen Resolution and select the resolution of your monitor © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Intro-11 Course Notes ► The Course Notes are organized to facilitate learning • Not intended to be used as a primary reference ► The Course Notes provide the big picture, then slowly fill in more detail • Suggested reference: standard Python documentation ◦ Available as Windows help files or online ◦ Online: https://docs.python.org/3/ • For more information, see Supplemental Course Materials (SCM) on My Learning Tree © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. Intro-12 Chapter 1 Object-Oriented Programming in Python Objectives ► Define Python classes and create objects ► Extend classes to define subclasses using inheritance © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. 1-2 Contents Python Feature Review ► OOP in Python ► Type Hinting ► Hands-On Exercise 1.1 © Learning Tree International, Inc. All rights reserved. Not to be reproduced without prior written consent. 1-3 Review: List Data Type ► list: Mutable ordered sequence of items • Create a list with [] cities = ['London', 'Ottawa', 'Stockholm'] populations = [8.6, 0.9, 0.9] # populations in millions ► To select a list item, use a numeric index print('The value of', cities[0], ' is', populations[0]) ► List operations • Select item by index: populations[1] • Select range of items (slice): cities[0:2] Selects items start to (end - 1) ◦ Selects ['London', 'Ottawa'] • Append item: cities.append('Washington DC') • Process all