Is there a way to loop through and execute all of the functions in a Python class?

Question

I have

class Foo():
    function bar():
        pass

    function foobar():
        pass

Rather than executing each function one by one as follows:

x = Foo()
x.bar()
x.foobar()

is there a built-in way to loop through and execute each function in the sequence in which they are written in the class?

Answer 1

def assignOrder(order):
  @decorator
  def do_assignment(to_func):
    to_func.order = order
    return to_func
  return do_assignment

class Foo():

  @assignOrder(1)
  def bar(self):
    print "bar"

  @assignOrder(2)
  def foo(self):
    print "foo"

  #don't decorate functions you don't want called
  def __init__(self):
    #don't call this one either!
    self.egg = 2

x = Foo()
functions = sorted(
             #get a list of fields that have the order set
             [
               getattr(x, field) for field in dir(x)
               if hasattr(getattr(x, field), "order")
             ],
             #sort them by their order
             key = (lambda field: field.order)
            )
for func in functions:
  func()

That funny @assignOrder(1) line above def bar(self) triggers this to happen:

Foo.bar = assignOrder(1)(Foo.bar)

assignOrder(1) returns a function that takes another function, changes it (adding the field order and setting it to 1) and returns it. This function is then called on the function it decorates (its order field gets thus set); the result replaces the original function.

It's a fancier, more readable and more maintainable way of saying:

  def bar(self):
    print "bar"
  Foo.bar.order = 1