class Foo:
def __init__(self, orig=None):
if orig is None:
self.non_copy_constructor()
else:
self.copy_constructor(orig)
def non_copy_constructor(self):
# do the non-copy constructor stuff
def copy_constructor(self, orig):
# do the copy constructor
a=Foo() # this will call the non-copy constructor
b=Foo(a) # this will call the copy constructor