Python Jumpstart by Building 10 Apps Transcripts
Chapter: App 7: Wizard Battle App
Lecture: Concept: Inheritance
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Inheritance is a core concept
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of all object oriented programming
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and it's exactly the tool that we need,
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to help us build these special types of creatures in our game,
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dragons, small animals and so on.
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The way it works is you declare what is called a base type,
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in our case this is the creature and it has all the common functionality.
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But we can add specialization to it,
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we can add some other type that is like a creature
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but has additional pieces of information, or behaviors,
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so here we have a dragon and the way we declare its base type,
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the thing that it gets its common behaviors from
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is we say "(" and the class name, ")".
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So dragon is a creature but dragons also have special behaviors and data
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so this dragon can bread fire, you can see there is breed fire method,
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creatures can do that, it's adding that to its specialization,
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and it also has a different set of data,
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it has a scale thickness in addition to the name and level.
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Now, notice this call to super, we say super.init,
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that's the initializer for the creature class,
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and we have to pass the name and the level onto this base class,
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we technically could ignore this step
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and then just store the name and level as well,
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but you often find you would be duplicating code
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and introducing various bugs by omission and so on, if you do that.
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Here we are actually letting the creature class
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deal with storing and processing the name and level
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and whatever that means and however that evolves over time,
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and we are only doing the extra stuff in the dragon,
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like storing the scale thickness and so on,
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so let's go back and apply this concept of inheritance
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to our wizard game.
