class Foo (object):
# ^class name #^ inherits from object
bar = "Bar" #Class attribute. def __init__(self): # #^ The first variable is the class instance in methods. # # This is called "self" by convention, but could be any name you want. #^ double underscore (dunder) methods are usually special. This one # gets called immediately after a new instance is created. self.variable = "Foo" #instance attribute. print self.variable, self.bar #<---self.bar references class attribute self.bar = " Bar is now Baz" #<---self.bar is now an instance attribute print self.variable, self.bar def method(self, arg1, arg2): #This method has arguments. You would call it like this: instance.method(1, 2) print "in method (args):", arg1, arg2 print "in method (attributes):", self.variable, self.bara = Foo() # this calls __init__ (indirectly), output: # Foo bar # Foo Bar is now Bazprint a.variable # Fooa.variable = "bar"a.method(1, 2) # output: # in method (args): 1 2 # in method (attributes): bar Bar is now BazFoo.method(a, 1, 2) #<--- Same as a.method(1, 2). This makes it a little more explicit what the argument "self" actually is.class Bar(object): def __init__(self, arg): self.arg = arg self.Foo = Foo()b = Bar(a)b.arg.variable = "something"print a.variable # somethingprint b.Foo.variable # Foo
