Python Classes and Objects

Basic Class and Subclass Syntax

__metaclass__ = type # use new style classes

class Artist:
    
    def setName(self, name):
        'Set the artist name.' # A doc string callable at Artist.setName.__doc__
        self.name = name
        
    def getName(self):
        return self.name
    
    def introduction(self):
        print "%s is an artist!" % self.name



# Create a subclass for sculptors.
class Sculptor(Artist):
    
    'Sculptor is a subclass of Artist'
    
    def introduction(self):
        'Overrides Artist.introduction()'
        print "%s is a sculptor!" % self.name



artist = Artist() # Create an instance of an artist
artist.setName('Vincent van Gogh') # Set name to Vincent van Gogh
print artist.getName() # Print to screen: Vincent van Gogh
artist.introduction() # Print to screen: Vincent van Gogh is an artist!
print artist.setName.__doc__ # Print to screen: Set the artist name

sculptor = Sculptor()
print sculptor.__doc__ # Print to screen:Sculptor is a subclass of Artist
sculptor.setName('Constantin Brancusi') # Set name to Constantin Brancusi
sculptor.introduction() # Print to screen: Constantin Brancusi is a sculptor!

Multiple Inheritance

class Foo:
    
    def alpha(self):
        print 'One'


class Bar:
    
    def beta(self):
        print 'Two'

        
class Baz:

    def alpha(self):
        print 'Three'


class Qux(Foo, Bar): pass


''' Note Baz will override Foo because it comes first! '''
class Quux(Baz, Foo): pass

Q = Qux()
Q.alpha() # Print to screen: One
Q.beta() # Print to screen: Two

Q2 = Quux()
Q2.alpha() # Print to screen: Three