Tiny Python Projects

Tiny Python Projects
brief contents
contents
preface
	Why write Python?
	Why did I write this book?
acknowledgments
about this book
	Who should read this book
	How this book is organized: A roadmap
	About the code
	Software/hardware requirements
	iiveBook discussion forum
	Other online resources
about the author
about the cover
Getting started: Introduction and installation guide
	Writing command-line programs
	Using test-driven development
	Setting up your environment
	Code examples
	Getting the code
	Installing modules
	Code formatters
	Code linters
	How to start writing new programs
	Why not Notebooks?
	The scope of topics we’ll cover
	Why not object-oriented programming?
	A note about the lingo
1 How to write and test a Python program
	1.1 Creating your first program
	1.2 Comment lines
	1.3 Testing your program
	1.4 Adding the #! (shebang) line
	1.5 Making a program executable
	1.6 Understanding $PATH
		1.6.1 Altering your $PATH
	1.7 Adding a parameter and help
	1.8 Making the argument optional
	1.9 Running our tests
	1.10 Adding the main() function
	1.11 Adding the get_args() function
		1.11.1 Checking style and errors
	1.12 Testing hello.py
	1.13 Starting a new program with new.py
	1.14 Using template.py as an alternative to new.py
	Summary
2 The crow’s nest: Working with strings
	2.1 Getting started
		2.1.1 How to use the tests
		2.1.2 Creating programs with new.py
		2.1.3 Write, test, repeat
		2.1.4 Defining your arguments
		2.1.5 Concatenating strings
		2.1.6 Variable types
		2.1.7 Getting just part of a string
		2.1.8 Finding help in the REPL
		2.1.9 String methods
		2.1.10 String comparisons
		2.1.11 Conditional branching
		2.1.12 String formatting
		2.1.13 Time to write
	2.2 Solution
	2.3 Discussion
		2.3.1 Defining the arguments with get_args()
		2.3.2 The main() thing
		2.3.3 Classifying the first character of a word
		2.3.4 Printing the results
		2.3.5 Running the test suite
	2.4 Going further
	Summary
3 Going on a picnic: Working with lists
	3.1 Starting the program
	3.2 Writing picnic.py
	3.3 Introducing lists
		3.3.1 Adding one element to a list
		3.3.2 Adding many elements to a list
		3.3.3 Indexing lists
		3.3.4 Slicing lists
		3.3.5 Finding elements in a list
		3.3.6 Removing elements from a list
		3.3.7 Sorting and reversing a list
		3.3.8 Lists are mutable
		3.3.9 Joining a list
	3.4 Conditional branching with if/elif/else
		3.4.1 Time to write
	3.5 Solution
	3.6 Discussion
		3.6.1 Defining the arguments
		3.6.2 Assigning and sorting the items
		3.6.3 Formatting the items
		3.6.4 Printing the items
	3.7 Going further
	Summary
4 Jump the Five: Working with dictionaries
	4.1 Dictionaries
		4.1.1 Creating a dictionary
		4.1.2 Accessing dictionary values
		4.1.3 Other dictionary methods
	4.2 Writing jump.py
	4.3 Solution
	4.4 Discussion
		4.4.1 Defining the parameters
		4.4.2 Using a dict for encoding
		4.4.3 Various ways to process items in a series
		4.4.4 (Not) using str.replace()
	4.5 Going further
	Summary
5 Howler: Working with files and STDOUT
	5.1 Reading files
	5.2 Writing files
	5.3 Writing howler.py
	5.4 Solution
	5.5 Discussion
		5.5.1 Defining the arguments
		5.5.2 Reading input from a file or the command line
		5.5.3 Choosing the output file handle
		5.5.4 Printing the output
		5.5.5 A low-memory version
	5.6 Going further
	Summary
6 Words count: Reading files and STDIN, iterating lists, formatting strings
	6.1 Writing wc.py
		6.1.1 Defining file inputs
		6.1.2 Iterating lists
		6.1.3 What you’re counting
		6.1.4 Formatting your results
	6.2 Solution
	6.3 Discussion
		6.3.1 Defining the arguments
		6.3.2 Reading a file using a for loop
	6.4 Going further
	Summary
7 Gashlycrumb: Looking items up in a dictionary
	7.1 Writing gashlycrumb.py
	7.2 Solution
	7.3 Discussion
		7.3.1 Handling the arguments
		7.3.2 Reading the input file
		7.3.3 Using a dictionary comprehension
		7.3.4 Dictionary lookups
	7.4 Going further
	Summary
8 Apples and Bananas: Find and replace
	8.1 Altering strings
		8.1.1 Using the str.replace() method
		8.1.2 Using str.translate()
		8.1.3 Other ways to mutate strings
	8.2 Solution
	8.3 Discussion
		8.3.1 Defining the parameters
		8.3.2 Eight ways to replace the vowels
	8.4 Refactoring with tests
	8.5 Going further
	Summary
9 Dial-a-Curse: Generating random insults from lists of words
	9.1 Writing abuse.py
		9.1.1 Validating arguments
		9.1.2 Importing and seeding the random module
		9.1.3 Defining the adjectives and nouns
		9.1.4 Taking random samples and choices
		9.1.5 Formatting the output
	9.2 Solution
	9.3 Discussion
		9.3.1 Defining the arguments
		9.3.2 Using parser.error()
		9.3.3 Program exit values and STDERR
		9.3.4 Controlling randomness with random.seed()
		9.3.5 Iterating with range() and using throwaway variables
		9.3.6 Constructing the insults
	9.4 Going further
	Summary
10 Telephone: Randomly mutating strings
	10.1 Writing telephone.py
		10.1.1 Calculating the number of mutations
		10.1.2 The mutation space
		10.1.3 Selecting the characters to mutate
		10.1.4 Mutating a string
		10.1.5 Time to write
	10.2 Solution
	10.3 Discussion
		10.3.1 Mutating a string
		10.3.2 Using a list instead of a str
	10.4 Going further
	Summary
11 Bottles of Beer Song: Writing and testing functions
	11.1 Writing bottles.py
		11.1.1 Counting down
		11.1.2 Writing a function
		11.1.3 Writing a test for verse()
		11.1.4 Using the verse() function
	11.2 Solution
	11.3 Discussion
		11.3.1 Counting down
		11.3.2 Test-driven development
		11.3.3 The verse() function
		11.3.4 Iterating through the verses
		11.3.5 1,500 other solutions
	11.4 Going further
	Summary
12 Ransom: Randomly capitalizing text
	12.1 Writing ransom.py
		12.1.1 Mutating the text
		12.1.2 Flipping a coin
		12.1.3 Creating a new string
	12.2 Solution
	12.3 Discussion
		12.3.1 Iterating through elements in a sequence
		12.3.2 Writing a function to choose the letter
		12.3.3 Another way to write list.append()
		12.3.4 Using a str instead of a list
		12.3.5 Using a list comprehension
		12.3.6 Using a map() function
	12.4 Comparing methods
	12.5 Going further
	Summary
13 Twelve Days of Christmas: Algorithm design
	13.1 Writing twelve_days.py
		13.1.1 Counting
		13.1.2 Creating the ordinal value
		13.1.3 Making the verses
		13.1.4 Using the verse() function
		13.1.5 Printing
		13.1.6 Time to write
	13.2 Solution
	13.3 Discussion
		13.3.1 Making one verse
		13.3.2 Generating the verses
		13.3.3 Printing the verses
	13.4 Going further
	Summary
14 Rhymer: Using regular expressions to create rhyming words
	14.1 Writing rhymer.py
		14.1.1 Breaking a word
		14.1.2 Using regular expressions
		14.1.3 Using capture groups
		14.1.4 Truthiness
		14.1.5 Creating the output
	14.2 Solution
	14.3 Discussion
		14.3.1 Stemming a word
		14.3.2 Formatting and commenting the regular expression
		14.3.3 Using the stemmer() function outside your program
		14.3.4 Creating rhyming strings
		14.3.5 Writing stemmer() without regular expressions
	14.4 Going further
	Summary
15 The Kentucky Friar: More regular expressions
	15.1 Writing friar.py
		15.1.1 Splitting text using regular expressions
		15.1.2 Shorthand classes
		15.1.3 Negated shorthand classes
		15.1.4 Using re.split() with a captured regex
		15.1.5 Writing the fry() function
		15.1.6 Using the fry() function
	15.2 Solution
	15.3 Discussion
		15.3.1 Writing the fry() function manually
		15.3.2 Writing the fry() function with regular expressions
	15.4 Going further
	Summary
16 The scrambler: Randomly reordering the middles of words
	16.1 Writing scrambler.py
		16.1.1 Breaking the text into lines and words
		16.1.2 Capturing, non-capturing, and optional groups
		16.1.3 Compiling a regex
		16.1.4 Scrambling a word
		16.1.5 Scrambling all the words
	16.2 Solution
	16.3 Discussion
		16.3.1 Processing the text
		16.3.2 Scrambling a word
	16.4 Going further
	Summary
17 Mad Libs: Using regular expressions
	17.1 Writing mad.py
		17.1.1 Using regular expressions to find the pointy bits
		17.1.2 Halting and printing errors
		17.1.3 Getting the values
		17.1.4 Substituting the text
	17.2 Solution
	17.3 Discussion
		17.3.1 Substituting with regular expressions
		17.3.2 Finding the placeholders without regular expressions
	17.4 Going further
	Summary
18 Gematria: Numeric encoding of text using ASCII values
	18.1 Writing gematria.py
		18.1.1 Cleaning a word
		18.1.2 Ordinal character values and ranges
		18.1.3 Summing and reducing
		18.1.4 Using functools.reduce
		18.1.5 Encoding the words
		18.1.6 Breaking the text
	18.2 Solution
	18.3 Discussion
		18.3.1 Writing word2num()
		18.3.2 Sorting
		18.3.3 Testing
	18.4 Going further
	Summary
19 Workout of the Day: Parsing CSV files, creating text table output
	19.1 Writing wod.py
		19.1.1 Reading delimited text files
		19.1.2 Manually reading a CSV file
		19.1.3 Parsing with the csv module
		19.1.4 Creating a function to read a CSV file
		19.1.5 Selecting the exercises
		19.1.6 Formatting the output
		19.1.7 Handling bad data
		19.1.8 Time to write
	19.2 Solution
	19.3 Discussion
		19.3.1 Reading a CSV file
		19.3.2 Potential runtime errors
		19.3.3 Using pandas.read_csv() to parse the file
		19.3.4 Formatting the table
	19.4 Going further
	Summary
20 Password strength: Generating a secure and memorable password
	20.1 Writing password.py
		20.1.1 Creating a unique list of words
		20.1.2 Cleaning the text
		20.1.3 Using a set
		20.1.4 Filtering the words
		20.1.5 Titlecasing the words
		20.1.6 Sampling and making a password
		20.1.7 l33t-ify
		20.1.8 Putting it all together
	20.2 Solution
	20.3 Discussion
		20.3.1 Cleaning the text
		20.3.2 A king’s ransom
		20.3.3 How to l33t()
		20.3.4 Processing the files
		20.3.5 Sampling and creating the passwords
	20.4 Going further
	Summary
21 Tic-Tac-Toe: Exploring state
	21.1 Writing tictactoe.py
		21.1.1 Validating user input
		21.1.2 Altering the board
		21.1.3 Printing the board
		21.1.4 Determining a winner
	21.2 Solution
		21.2.1 Validating the arguments and mutating the board
		21.2.2 Formatting the board
		21.2.3 Finding the winner
	21.3 Going further
	Summary
22 Tic-Tac-Toe redux: An interactive version with type hints
	22.1 Writing itictactoe.py
		22.1.1 Tuple talk
		22.1.2 Named tuples
		22.1.3 Adding type hints
		22.1.4 Type verification with Mypy
		22.1.5 Updating immutable structures
		22.1.6 Adding type hints to function definitions
	22.2 Solution
		22.2.1 A version using TypedDict
		22.2.2 Thinking about state
	22.3 Going further
	Summary
Epilogue
Appendix—Using argparse
	A.1 Types of arguments
	A.2 Using a template to start a program
	A.3 Using argparse
		A.3.1 Creating the parser
		A.3.2 Creating a positional parameter
		A.3.3 Creating an optional string parameter
		A.3.4 Creating an optional numeric parameter
		A.3.5 Creating an optional file parameter
		A.3.6 Creating a flag option
		A.3.7 Returning from get_args
	A.4 Examples using argparse
		A.4.1 A single positional argument
		A.4.2 Two different positional arguments
		A.4.3 Restricting values using the choices option
		A.4.4 Two of the same positional arguments
		A.4.5 One or more of the same positional arguments
		A.4.6 File arguments
		A.4.7 Manually checking arguments
		A.4.8 Automatic help
	Summary
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