The Python Apprentice

Table of Contents
Preface
	Errata and Suggestions
	Conventions Used in This Book
	Code examples
Welcome Apprentice!
Python Promo
Overview
What is Python?
	It's a programming language!
	It's a standard library!
	It's a philosophy
The journey of a thousand miles…
Chapter 1 – Getting started
	Obtaining and installing Python 3
	Starting Python command line REPL
	Leaving the REPL
	Code structure and significant indentation
	Python culture
	Importing standard library modules
	Getting help()
	Scalar data types: integers, floats, None and bool
	Relational operators
	Control flow: if-statements and while-loops
	Summary
Chapter 2 – Strings and collections
	str – an immutable sequence of Unicode code points
	Moment of zen
	bytes – an immutable sequence of bytes
	list – a sequence of objects
	dict – associating keys with values
	For-loops – iterating over series of items
	Putting it all together
	Summary
Chapter 3 – Modularity
	Organizing code in a .py file
	Defining functions
	Organizing our module into functions
	The Python execution model
	Setting up a main function with command line argument
	Moment of zen
	Docstrings
	Comments
	Shebang
	Summary
Chapter 4 – Built-in types and the object model
	The nature of Python object references
	Argument passing semantics – pass by object-reference
	Python return semantics
	Function arguments in detail
	The Python type system
	Variable declaration and scoping
	Moment of zen
	Everything is an object
	Summary
Chapter 5 – Exploring built-in collection types
	tuple – an immutable sequence of objects
	The tuple constructor
	Strings in action
	Moment of zen
	range – a collection of evenly spaced integers
	list in action
	Dictionaries
	set – an unordered collection of unique elements
	Collection protocols
	Summary
Chapter 6 – Exceptions
	Exceptions and control flow
	Handling exceptions
	Handling multiple exceptions
	Programmer errors
	Empty blocks – the pass statement
	Exception objects
	Imprudent return codes
	Re-raising exceptions
	Exceptions are part of your function's API
	Guard clauses
	Exceptions, APIs, and protocols
	Choosing not to guard against TypeError
	Pythonic style – EAFP versus LBYL
	Clean-up actions
	Moment of zen
	Platform-specific code
	Summary
Chapter 7 - Comprehensions, iterables, and generators
	Comprehensions
	Moment of zen
	Iteration protocols
	Generator functions
	Generator expressions
	``Batteries included'' iteration tools
	Pulling it all together
	Summary
Chapter 8 – Defining new types with classes
	Defining classes
	Instance methods
	Instance initializers
	Validation and invariants
	Adding a second class
	Collaborating classes
	Moment of zen
	Booking seats
	Naming methods for implementation details
	Sometimes the only object you need is a function
	Polymorphism and duck-typing
	Inheritance and implementation sharing
	Summary
Chapter 9 – Files and resource management
	Files
	Context managers
	Moment of zen
	Binary files
	File-like objects
	Other resources
	Summary
Chapter 10 – Unit testing with the Python standard library
	Test cases
	Fixtures
	Assertions
	Unit testing example: text analysis
	Using fixtures to create temporary files
	Using the new fixtures
	Using assertions to test behavior
	Testing for exceptions
	Testing for file existence
	Moment of zen
	Summary
Chapter 11 – Debugging with PDB
	Debugging commands
	Palindrome debugging
	Summary
Afterword: Just the Beginning
Appendix A – Virtual environments
	Creating a virtual environment
	Activating a virtual environment
	Deactivating a virtual environment
	Other tools for working with virtual environments
Appendix B – Packaging and distribution
	Configuring a package with distutils
	Installing with distutils
	Packaging with distutils
Appendix C – Installing third-party packages
	Introducing pip
	The Python Package Index
	Installing local packages with pip
	Uninstalling packages