Python Jumpstart by Building 10 Apps Transcripts
Chapter: App 7: Wizard Battle App
Lecture: Introduction to the Wizard Battle App
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It's time for app number 7,
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and this time we are going to build a really fun wizard game
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it's kind of a role playing dungeons and dragons sort of thing.
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So what is that going to look like?
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Well, it's going to be a text based game
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and here you can see a standard ground of game play.
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Of course, like all of our apps we start with a little header that says what the app is,
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and then right off bat we have our hero in the game, the wizard Gandolf.
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And he sees an Evil Wizard.
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It turn out that one is super strong
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and so he is like... I am not going to battle this, he could attack it,
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he could look around, but he is just going to run away as quick as he can.
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So he does, and then next he finds a Bat, and decides
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hey, I can probably attack and kill this Bat, so he does,
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but just barely he roles a 22, the bat roles at 22
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and I guess because the element of surprise
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the wizard was triumphant over the Bat.
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After that, the wizard Gandolf decides to have a look around
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and he sees that there is a wimpy toad, a tiger, a dragon
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and that very strong evil wizard hanging around.
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The game goes around and around like this,
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until either all the creatures are defeated or the wizard is gone.
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While building this game we are going to learn
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one of the most important concepts in all of computer programming
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and that is the concept of object oriented programming.
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This starts with defining classes
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and classes defined how data and behavior
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are bundled into one concept in programming
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maybe this is a wizard or a dragon
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or the general concept of a creature
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or even the concept of a game itself.
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When we create these classes, these are called objects,
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we want to initialize them,
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have them come into existence immediately with the data they need,
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we'll do that through initializers
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and when we are talking about inheritance
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we have to chain those initializers through the inheritance tree,
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so we are going to talk about initializer chaining.
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Speaking of inheritance, that lets us model our concepts
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in our program with different levels of specialization.
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So we can model all of the actors, the dragon, the toad, the wizard
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as something maybe we'll call the creature in the game
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and then we have a specialized version of the creature
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that has other data and other features called the wizard
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and it knows how to battle creatures
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and then we can also have different types of creatures
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that may themselves have special features
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like a dragon that has a special attack or something like that.
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So this is called inheritance and it's a very powerful feature, when use judiciously.
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When we talk about inheritance,
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we are also going to talk about polymorphism and duck typing.
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Some languages have very strict rules
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about how you can use the more general what you call a base class
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or the specialized derived class,
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like how you can use a creature versus how to use a wizard,
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the compiler checks all these things and so on,
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Python doesn't have compiling or this concept of strong typing
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instead we are going to use something called duck typing
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we'll talk about that near the end of our app.
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Let's get onto build a super fun dungeons and dragon style wizard game.
