A quick introdution to Python classes

classes.py

# This is the new style way of declaring classes and should be preferred
# Python screwed up the way classes and typing works the first go round,
# but they fixed it with new style classes
class Object(object):
	# This is the constructor. It takes an instance of the object and a single argument called foo.
	def __init__(self, foo):
		# Make foo a property of this instance
		self.foo = foo
	# Add n to foo. Note that if foo is a string, n must also be a string,
	# or if foo is a numeric type, foo must also be numeric
	def add(self, n):
		self.foo += foo

	#This really doesn't make too much sense in context, but it's an example
	def __len__(self):
		return foo

o = Object(2) # calls __init__ for you
o.add(2) # Equivalent to Object.add(o, 2)

print len(o) # calls Object.__len__