book

Head First Learn to Code

Name: Head First Learn to Code
Author: Eric Freeman
ISBN: 9781491958865

by Eric Freeman

January 2018

Beginner

639 pages

15h 54m

English

O'Reilly Media, Inc.

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Praise for Head First Learn to Code
Praise for other books by Eric Freeman
Head First Learn to Code
the author
how to use this book: Intro
Who is this book for?Who should probably back away from this book?We know what you’re thinking.And we know what your brain is thinking.Metacognition: thinking about thinkingSo how DO you get your brain to think coding is as important as a tiger?Here’s what WE did:Here’s what YOU can do to bend your brain into submissionRead MeWe want you to learn the thinking process behind programming.In this book we use Python.We don’t exhaustively cover every aspect of the Python language.You can use a Mac or PC, or Linux for that matter.The activities are NOT optional.The redundancy is intentional and important.The examples are as lean as possible.The Brain Power exercises don’t usually have answers.Get the code examples, help, and discussion online.You’re going to have to install PythonA word on organizing your codeAcknowledgments*The Review Team
1. 1 thinking computationally: Getting Started
Breaking it downHow coding worksAre we even speaking the same language?The world of programming languagesHow you’ll write and run code with Pythonthere are no Dumb QuestionsA very brief history of PythonPutting Python through its pacesSaving your workCongrats on coding your first Python program!there are no Dumb QuestionsPhrase-O-MaticGetting the code in the machine
2. 2 simple values, variables, and types: Know Your Value
Coding the Dog Age CalculatorGoing from pseudocode to codeStep 1: Getting some inputHow the input function worksUsing variables to remember and store valuesAssigning the user’s input to a variableStep 2: Getting more inputIt’s time to run some codeGetting some code enteredA deep dive on variablesAdding some expressionVariables are called VARY-ables for a reasonBetter living through operator precedenceComputing with operator precedenceCrack the Code ChallengeBack away from that keyboard!there are no Dumb QuestionsStep 3: Computing the dog’s ageHouston, we’ve got a problem!To err is human to codeA little more debugging...Careful what you ask for...What are Python types, anyway?there are no Dumb QuestionsFixing our codethere are no Dumb QuestionsHouston, we have liftoffStep 4: User-friendly outputWho am I? SolutionCrack the Code Challenge SOLUTION
3. 3 booleans, decisions, and loops: Decisive Code
Would you like to play a game?How Rock, Paper, Scissors worksHow you’re going to play against the computerFirst, a high-level designThe computer’s choiceHow to generate a random numberHow to use the random numberthere are no Dumb QuestionsTaking things further...True? Or False?Introducing the Boolean typeMaking decisionsDecisions and more decisionsBack to Rock, Paper, ScissorsGetting the user’s choiceGood eye.Taking a look at the user’s choiceAdding the code to detect a tieWho won?Right.How to implement the game logicMore about Boolean operatorsDisplay the winnerGot documentation?How to add comments to your codeWe need to finish that game!How do we know if the user’s choice is invalid?Checking out and cleaning up the expressionHow to continually prompt the userDoing things more than onceHow the while loop worksHow to use while to prompt the user until you get a valid choiceCongratulations on coding your first game!Beware of the The Dreaded Infinite Loop
4. 4 lists and iteration: Providing Some Structure
Can you help Bubbles-R-Us?How to represent multiple values in PythonHow lists workHow to create a listHow to access a list itemUpdating a value in the listHow big is that list, anyway?Accessing the last item in the listPython makes this even easierUsing Python’s negative indicesthere are no Dumb QuestionsMeanwhile, back at Bubbles-R-Us...Cubicle conversationHow to iterate over a listFixing the output glitchReally fixing the output glitchThe for loop, the preferred way to iterate over a listHow the for loop worksHow the for loop works on a range of numbersDoing more with rangesTry a starting and ending numberAdd a step sizeCount backwardOr start from negative numbersthere are Dumb QuestionsPutting it all togetherTest drive the bubble report Fireside ChatsCubicle conversation continued...Building your own list, from scratchDoing even more with listsDelete an item from a listAdd one list to anotherOr insert items into your listthere are no Dumb QuestionsTest drive the final report And the winners are... Testing the most cost-effective solutionYou’re right: we didn’t need to.

5. 5 functions and abstraction: Getting Functional
What’s wrong with the code, anyway?Turning a block of code into a FUNCTIONWe created a function, so how do we use it?But how does all this actually work?there are no Dumb QuestionsFunctions can RETURN things tooHow to call a function that has a return valueGood catch.Getting a little refactoring under our beltsRunning the codeHow to abstract the avatar codeWriting the get attribute function bodyCalling get attributeLet’s talk about variables a little more...Understanding variable scopethere are no Dumb QuestionsWhen variables get passed to functionsMaking the drink_me function callWhat about using global variables in functions?Fireside ChatsGoing further with parameters: default values and keywordsHow default parameter values workAlways list your required parameters first!Using arguments with keywordsHow to think about all these optionsThe case of the attempted robbery not worth investigating
6. 4, part 2, sorting and nested iteration: Putting Some Order in Your Data
Cubicle conversationUnderstanding bubble sortStarting with pass 1Pass 2Pass 3Some bubble sort pseudocodeCubicle conversation continued...Implementing bubble sort in PythonComputing bubble solution numbers
7. 6 text, strings, and heuristics: Putting It All Together
Welcome to the data sciencesHow do you compute something like readability?The game planWriting some pseudocodeWe need some text to analyzeHow to get multiline text into PythonSetting up the functionFirst up: we need the total number of words in our textCubicle conversationthere are no Dumb QuestionsComputing the total number of sentencesWriting the count_sentences functionComputing the number of syllables, or, learning to love heuristicsCubicle conversation continued...Setting up the heuristicWriting the heuristicHow to count vowelsIgnoring consecutive vowelsWriting the code to ignore consecutive vowelsRemoving final e’s, y’s, and punctuationHe who controls the slice, controls the...Putting slicing (substrings) to workFinishing off the heuristic codeImplementing the reading ease formulaTaking it even further
8. 7 modules, methods, classes, and objects: Getting Modular
Cubicle conversationA quick module reviewthere are no Dumb QuestionsCubicle conversation continued...The name global variableCubicle conversation continued...Updating analyze.pyUsing analyze.py as a moduleAdding docstrings to analyze.pyExploring other Python modulesWait, did someone say “turtles”?!Creating your very own turtleTurtle labthere are no Dumb QuestionsAdding a second turtleWhat are turtles, anyway?What are objects?Okay, what’s a class then?A class is not an object, it’s used to construct them.there are no Dumb QuestionsA class tells us what an object knows and what an object can doHow to use objects and classesWhat about those methods and attributes?Seeing classes and objects everywhereGet ready for some turtle racesPlanning the gameLet’s start codingSetting up the gameWriting the setup codeNot so fast!Starting the raceDon’t worry, this isn’t the end of objects.Odd goings-on at the turtle races. Mod coding cross Mod cross Solution
9. 8 recursion and dictionaries: Beyond Iteration and Indices
A different way to computeAnd now the different way...Now let’s write some code for our two casesLet’s get some more practiceUsing recursion to detect palindromesWriting a recursive palindrome detectorthere are no Dumb QuestionsFireside ChatsThe Anti-Social NetworkIntroducing the dictionaryLet’s see how to create a dictionaryAnd then add itemsAnd then retrieve values by their keysKeys and values do not have to be stringsOf course you can remove keys as wellBut you might want to test to see if it exists firstthere are no Dumb QuestionsWhat about iterating through a dictionary?Okay, but can we get literal for a sec?Leveraging dictionaries at the Anti-Social NetworkBut how do we add more attributes?Remember the Anti-Social Network’s killer feature?Finding the most anti-social userNow, it’s all you!Can we just remember function call results?Using a dictionary to remember our Fibonacci resultsWe might as well use the $5 words: memoization Some more brain buildingA closer look at the koch functionTruly exploring the koch fractalThey don’t call it the Koch snowflake for nothin’
10. 9 saving and retrieving files: Persistence
Ready for some Crazy Libs?How to PlayHow Crazy Libs is going to workStep 1: Read the text of the story from a fileTo read a file in Python, you first have to open itHow to use file pathsRelative pathsAbsolute pathsOh, and don’t forget to clean up when you’re done!Reading a file into your Python codeUsing the file object to read a fileOh, give it a break already...Hey, we’ve got a Crazy Lib game to finish!Using the readline method of the file objectHow do we know when we’ve read the last line?Ah, but there’s a easier way using the power of Python sequencesReading in a Crazy Lib templateProcessing the template textNow let’s process the textUsing a new string method to fix the bugActually fixing the bugSome code has real problemsHandling exceptionsExplicitly handling exceptionsthere are Dumb QuestionsUpdating Crazy Libs to handle exceptionsOur last step: storing the Crazy LibUpdating the rest of the code File i/o cross Solution
11. 10 using web apis: You Really Should Get Out More
Extending your reach with Web APIsHow Web APIs workAll Web APIs have a web addressConsult the API documentation.Good point.Time for a quick upgradeDoing the upgradethere are no Dumb QuestionsAll we need now is a good Web API...A closer look at the APIWeb APIs provide data using JSONthere are no Dumb QuestionsNow let’s look at that request module againPutting it all together: making a request to Open NotifyHow to use JSON in PythonUsing the JSON module on our ISS dataLet’s add some graphicsMeet the screen objectLet’s add a turtle to represent the ISSTurtles can look like space stations tooForget the ISS—where are we?Finishing off the ISS code
12. 11 widgets, events, and emergent behavior: Getting Interactive
A closer look at the Game of LifeOh, you’d be surprised...What we’re going to buildDo we have the right design?How we’re going to build the simulatorBuilding the data modelRepresenting the gridComputing a generation of the Game of LifeComputing each cell’s fateCompleting the model codeWhere are we?Building the viewCreating your first widgetAdding the rest of the widgetsCorrecting the layoutPlacing the widgets into a grid layoutTranslating the grid layout to codethere are no Dumb QuestionsMoving on to the controllerAdding an update functionthere are no Dumb QuestionsReady for another new style of computation?Let’s add a click handlerHow the start/pause button is going to workImplementing the start/pause buttonAnother kind of eventWe have the technology: the after methodAre we there yet?How to enter and edit cells directlyWriting the grid_view handlerNow it’s time to add some patternsWriting a handler for the OptionMenuHow to define your patternsWriting the pattern loader
13. 12 object-oriented programming: A Trip to Objectville
Breaking it down, a different wayWhat’s the point of object-oriented programming, anyway?Designing your first classWriting your first classHow the constructor worksthere are no Dumb QuestionsWriting the bark methodHow methods workAdding some inheritanceImplementing the ServiceDog classA closer look at subclassingA ServiceDog IS-A DogTesting IS-A in codeHow would you describe yourself?there are no Dumb QuestionsOverriding and extending behaviorWelcome to Jargon CityObject can HAS-Another objectDesigning a Doggie HotelImplementing the Doggie HotelRenovating the Doggie HotelAdding some hotel activitiesI can do anything you can, or PolymorphismIt’s about time we teach the other dogs to walkThe power of inheritanceCreating a Doggie Hotel walking serviceHow are we going to hire a person to walk our dogs if we don’t even have people objects?Meanwhile, back at the turtle races…The turtle races case SOLVEDHave you considered a career in coding?
A. appendix: leftovers: The Top Ten Topics (We Didn’t Cover)
#1 List comprehensions#2 Dates and times#3 Regular expressions#4 Other data types: tuples#5 Other data types: sets#6 Server-side coding#7 Lazy evaluation#8 Decorators#9 Higher-order and first-class functions#10 A lot of librariesDon’t worry, this isn’t goodbye.
B. Bring your brain over to wickedlysmart.com
Index
SymbolsABCDEFGHIJKLMNOPQRSTUVWYZ

Content preview from Head First Learn to Code

the author

Eric is described by Head First series co-creator Kathy Sierra as “one of those rare individuals fluent in the language, practice, and culture of multiple domains from hipster hacker, corporate VP, engineer, think tank.” And his background matches that description well. By training, Eric is a computer scientist, having studied with industry luminary David Gelernter during his Ph.D. work at Yale University. Professionally, Eric is a former media company executive—having held the position of CTO of Disney.com at The Walt Disney Company. Eric has also held positions at O’Reilly Media, NASA, and several startups, and his IP is licensed and in use on every Mac and PC. Over the last 15 years Eric has been one of the top-selling technical authors on topics from beginning web development to high-level software design.

Eric is currently is a Principal at WickedlySmart, LLC, and lives with his wife and young daughter in Austin, Texas.

Write to Eric at eric@wickedlysmart.com or visit http://wickedlysmart.com.

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Head First Learn to Code

by Eric Freeman

the author

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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