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copied!<p>Classes in Python are basically just ways of grouping a bunch of functions and data.. They are different to classes in C++ and such..</p> <p>I've mostly seen inheritance used for overriding methods of the super-class. For example, perhaps a more Python'ish use of inheritance would be..</p> <pre><code>from world.animals import Dog class Cat(Dog): def speak(self): print "meow" </code></pre> <p>Of course cats aren't a type of dog, but I have this (third party) <code>Dog</code> class which works perfectly, <em>except</em> the <code>speak</code> method which I want to override - this saves re-implementing the entire class, just so it meows. Again, while <code>Cat</code> isn't a type of <code>Dog</code>, but a cat does inherit a lot of attributes..</p> <p>A much better (practical) example of overriding a method or attribute is how you change the user-agent for urllib. You basically subclass <code>urllib.FancyURLopener</code> and change the version attribute (<a href="http://docs.python.org/library/urllib.html#urllib._urlopener" rel="nofollow noreferrer">from the documentation</a>):</p> <pre><code>import urllib class AppURLopener(urllib.FancyURLopener): version = "App/1.7" urllib._urlopener = AppURLopener() </code></pre> <p>Another manner exceptions are used is for Exceptions, when inheritance is used in a more "proper" way:</p> <pre><code>class AnimalError(Exception): pass class AnimalBrokenLegError(AnimalError): pass class AnimalSickError(AnimalError): pass </code></pre> <p>..you can then catch <code>AnimalError</code> to catch all exceptions which inherit from it, or a specific one like <code>AnimalBrokenLegError</code></p>

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