book

Tiny Python Projects

Name: Tiny Python Projects
Author: Ken Youens-Clark
ISBN: 9781617297519

by Ken Youens-Clark

August 2020

Beginner

440 pages

12h 2m

English

Manning Publications

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Tiny Python Projects
Copyright
brief contents
contents
front matter
prefaceWhy write Python?Why did I write this book?acknowledgmentsabout this bookWho should read this bookHow this book is organized: A roadmapAbout the codeSoftware/hardware requirementsiiveBook discussion forumOther online resourcesabout the authorabout the cover
0 Getting started: Introduction and installation guide
Writing command-line programsUsing test-driven developmentSetting up your environmentCode examplesGetting the codeInstalling modulesCode formattersCode lintersHow to start writing new programsWhy not Notebooks?The scope of topics we’ll coverWhy not object-oriented programming?A note about the lingo
1 How to write and test a Python program
1.1 Creating your first program1.2 Comment lines1.3 Testing your program1.4 Adding the #! (shebang) line1.5 Making a program executable1.6 Understanding $PATH1.6.1 Altering your $PATH1.7 Adding a parameter and help1.8 Making the argument optional1.9 Running our tests1.10 Adding the main() function1.11 Adding the get_args() function1.11.1 Checking style and errors1.12 Testing hello.py1.13 Starting a new program with new.py1.14 Using template.py as an alternative to new.pySummary
2 The crow’s nest: Working with strings
2.1 Getting started2.1.1 How to use the tests2.1.2 Creating programs with new.py2.1.3 Write, test, repeat2.1.4 Defining your arguments2.1.5 Concatenating strings2.1.6 Variable types2.1.7 Getting just part of a string2.1.8 Finding help in the REPL2.1.9 String methods2.1.10 String comparisons2.1.11 Conditional branching2.1.12 String formatting2.1.13 Time to write2.2 Solution2.3 Discussion2.3.1 Defining the arguments with get_args()2.3.2 The main() thing2.3.3 Classifying the first character of a word2.3.4 Printing the results2.3.5 Running the test suite2.4 Going furtherSummary
3 Going on a picnic: Working with lists
3.1 Starting the program3.2 Writing picnic.py3.3 Introducing lists3.3.1 Adding one element to a list3.3.2 Adding many elements to a list3.3.3 Indexing lists3.3.4 Slicing lists3.3.5 Finding elements in a list3.3.6 Removing elements from a list3.3.7 Sorting and reversing a list3.3.8 Lists are mutable3.3.9 Joining a list3.4 Conditional branching with if/elif/else3.4.1 Time to write3.5 Solution3.6 Discussion3.6.1 Defining the arguments3.6.2 Assigning and sorting the items3.6.3 Formatting the items3.6.4 Printing the items3.7 Going furtherSummary
4 Jump the Five: Working with dictionaries
4.1 Dictionaries4.1.1 Creating a dictionary4.1.2 Accessing dictionary values4.1.3 Other dictionary methods4.2 Writing jump.py4.3 Solution4.4 Discussion4.4.1 Defining the parameters4.4.2 Using a dict for encoding4.4.3 Various ways to process items in a series4.4.4 (Not) using str.replace()4.5 Going furtherSummary

5 Howler: Working with files and STDOUT
5.1 Reading files5.2 Writing files5.3 Writing howler.py5.4 Solution5.5 Discussion5.5.1 Defining the arguments5.5.2 Reading input from a file or the command line5.5.3 Choosing the output file handle5.5.4 Printing the output5.5.5 A low-memory version5.6 Going furtherSummary
6 Words count: Reading files and STDIN, iterating lists, formatting strings
6.1 Writing wc.py6.1.1 Defining file inputs6.1.2 Iterating lists6.1.3 What you’re counting6.1.4 Formatting your results6.2 Solution6.3 Discussion6.3.1 Defining the arguments6.3.2 Reading a file using a for loop6.4 Going furtherSummary
7 Gashlycrumb: Looking items up in a dictionary
7.1 Writing gashlycrumb.py7.2 Solution7.3 Discussion7.3.1 Handling the arguments7.3.2 Reading the input file7.3.3 Using a dictionary comprehension7.3.4 Dictionary lookups7.4 Going furtherSummary
8 Apples and Bananas: Find and replace
8.1 Altering strings8.1.1 Using the str.replace() method8.1.2 Using str.translate()8.1.3 Other ways to mutate strings8.2 Solution8.3 Discussion8.3.1 Defining the parameters8.3.2 Eight ways to replace the vowels8.4 Refactoring with tests8.5 Going furtherSummary
9 Dial-a-Curse: Generating random insults from lists of words
9.2 Writing abuse.py9.1.1 Validating arguments9.1.2 Importing and seeding the random module9.1.3 Defining the adjectives and nouns9.1.4 Taking random samples and choices9.1.5 Formatting the output9.2 Solution9.3 Discussion9.3.1 Defining the arguments9.3.2 Using parser.error()9.3.3 Program exit values and STDERR9.3.4 Controlling randomness with random.seed()9.3.5 Iterating with range() and using throwaway variables9.3.6 Constructing the insults9.4 Going furtherSummary
10 Telephone: Randomly mutating strings
10.1 Writing telephone.py10.1.1 Calculating the number of mutations10.1.2 The mutation space10.1.3 Selecting the characters to mutate10.1.4 Mutating a string10.1.5 Time to write10.2 Solution10.3 Discussion10.3.1 Mutating a string10.3.2 Using a list instead of a str10.4 Going furtherSummary
11 Bottles of Beer Song: Writing and testing functions
11.1 Writing bottles.py11.1.1 Counting down11.1.2 Writing a function11.1.3 Writing a test for verse()11.1.4 Using the verse() function11.2 Solution11.3 Discussion11.3.1 Counting down11.3.2 Test-driven development11.3.3 The verse() function11.3.4 Iterating through the verses11.3.5 1,500 other solutions11.4 Going furtherSummary
12 Ransom: Randomly capitalizing text
12.1 Writing ransom.py12.1.1 Mutating the text12.1.2 Flipping a coin12.1.3 Creating a new string12.2 Solution12.3 Discussion12.3.1 Iterating through elements in a sequence12.3.2 Writing a function to choose the letter12.3.3 Another way to write list.append()12.3.4 Using a str instead of a list12.3.5 Using a list comprehension12.3.6 Using a map() function12.4 Comparing methods12.5 Going furtherSummary
13 Twelve Days of Christmas: Algorithm design
13.1 Writing twelve_days.py13.1.1 Counting13.1.2 Creating the ordinal value13.1.3 Making the verses13.1.4 Using the verse() function13.1.5 Printing13.1.6 Time to write13.2 Solution13.3 Discussion13.3.1 Making one verse13.3.2 Generating the verses13.3.3 Printing the verses13.4 Going furtherSummary
14 Rhymer: Using regular expressions to create rhyming words
14.1 Writing rhymer.py14.1.1 Breaking a word14.1.2 Using regular expressions14.1.3 Using capture groups14.1.4 Truthiness14.1.5 Creating the output14.2 Solution14.3 Discussion14.3.1 Stemming a word14.3.2 Formatting and commenting the regular expression14.3.3 Using the stemmer() function outside your program14.3.4 Creating rhyming strings14.3.5 Writing stemmer() without regular expressions14.4 Going furtherSummary
15 The Kentucky Friar: More regular expressions
15.1 Writing friar.py15.1.1 Splitting text using regular expressions15.1.2 Shorthand classes15.1.3 Negated shorthand classes15.1.4 Using re.split() with a captured regex15.1.5 Writing the fry() function15.1.6 Using the fry() function15.2 Solution15.3 Discussion15.3.1 Writing the fry() function manually15.3.2 Writing the fry() function with regular expressions15.4 Going furtherSummary
16 The scrambler: Randomly reordering the middles of words
16.1 Writing scrambler.py16.1.1 Breaking the text into lines and words16.1.2 Capturing, non-capturing, and optional groups16.1.3 Compiling a regex16.1.4 Scrambling a word16.1.5 Scrambling all the words16.2 Solution16.3 Discussion16.3.1 Processing the text16.3.2 Scrambling a word16.4 Going furtherSummary
17 Mad Libs:Using regular expressions
17.1 Writing mad.py17.1.1 Using regular expressions to find the pointy bits17.1.2 Halting and printing errors17.1.3 Getting the values17.1.4 Substituting the text17.2 Solution17.3 Discussion17.3.1 Substituting with regular expressions17.3.2 Finding the placeholders without regular expressions17.4 Going furtherSummary
18 Gematria: Numeric encoding of text using ASCII values
18.1 Writing gematria.py18.1.1 Cleaning a word18.1.2 Ordinal character values and ranges18.1.3 Summing and reducing18.1.4 Using functools.reduce18.1.5 Encoding the words18.1.6 Breaking the text18.2 Solution18.3 Discussion18.3.1 Writing word2num()18.3.2 Sorting18.3.3 Testing18.4 Going furtherSummary
19 Workout of the Day: Parsing CSV files, creating text table output
19.1 Writing wod.py19.1.1 Reading delimited text files19.1.2 Manually reading a CSV file19.1.3 Parsing with the csv module19.1.4 Creating a function to read a CSV file19.1.5 Selecting the exercises19.1.6 Formatting the output19.1.7 Handling bad data19.1.8 Time to write19.2 Solution19.3 Discussion19.3.1 Reading a CSV file19.3.2 Potential runtime errors19.3.3 Using pandas.read_csv() to parse the file19.3.4 Formatting the table19.4 Going furtherSummary
20 Password strength: Generating a secure and memorable password
20.1 Writing password.py20.1.1 Creating a unique list of words20.1.2 Cleaning the text20.1.3 Using a set20.1.4 Filtering the words20.1.5 Titlecasing the words20.1.6 Sampling and making a password20.1.7 l33t-ify20.1.8 Putting it all together20.2 Solution20.3 Discussion20.3.1 Cleaning the text20.3.2 A king’s ransom20.3.3 How to l33t()20.3.4 Processing the files20.3.5 Sampling and creating the passwords20.4 Going furtherSummary
21 Tic-Tac-Toe: Exploring state
21.1 Writing tictactoe.py21.1.1 Validating user input21.1.2 Altering the board21.1.3 Printing the board21.1.4 Determining a winner21.2 Solution21.2.1 Validating the arguments and mutating the board21.2.2 Formatting the board21.2.3 Finding the winner21.3 Going furtherSummary
22 Tic-Tac-Toe redux: An interactive version with type hints
22.1 Writing itictactoe.py22.1.1 Tuple talk22.1.2 Named tuples22.1.3 Adding type hints22.1.4 Type verification with Mypy22.1.5 Updating immutable structures22.1.6 Adding type hints to function definitions22.2 Solution22.2.1 A version using TypedDict22.2.2 Thinking about state22.3 Going furtherSummary
Epilogue
Appendix. Using argparse
A.1 Types of argumentsA.2 Using a template to start a programA.3 Using argparseA.3.1 Creating the parserA.3.2 Creating a positional parameterA.3.3 Creating an optional string parameterA.3.4 Creating an optional numeric parameterA.3.5 Creating an optional file parameterA.3.6 Creating a flag optionA.3.7 Returning from get_argsA.4 Examples using argparseA.4.1 A single positional argumentA.4.2 Two different positional argumentsA.4.3 Restricting values using the choices optionA.4.4 Two of the same positional argumentsA.4.5 One or more of the same positional argumentsA.4.6 File argumentsA.4.7 Manually checking argumentsA.4.8 Automatic helpSummary
index

Content preview from Tiny Python Projects

4 Jump the Five: Working with dictionaries

“When I get up, nothing gets me down.”

--D. L. Roth

In an episode of the television show The Wire, drug dealers assume the police are intercepting their text messages. Whenever a phone number needs to be texted in the course of a criminal conspiracy, the dealers will obfuscate the number. They use an algorithm we’ll call “Jump the Five” because each number is changed to its mate on the opposite of a US telephone pad if you jump over the 5. In this exercise, we’ll discuss how to encrypt messages using this algorithm, and then we’ll see how to use it to decrypt the encrypted messages, you feel me?

If we start with the 1 button and jump across the 5, we get to 9. The 6 jumps the 5 to become ...

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Tiny Python Projects

by Ken Youens-Clark

4 Jump the Five: Working with dictionaries

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