On May 20, 8:55 pm, manstey <[EMAIL PROTECTED]> wrote: > Hi, > > I have a simple subclass of a list: > > class CaListOfObj(list): > """ subclass of list """ > def __init__(self, *args, **kwargs): > list.__init__(self, *args, **kwargs) > > a= CaListOfObj([1,2,3]) > > How do I write a method that does something EVERY time a is modified? > > Thanks
You could overridge the __setitem__ and __setslice__ methods like so. def somefunc(): print 'Hello There' class CaListOfObj(list): """ subclass of list """ def __init__(self, *args, **kwargs): list.__init__(self, *args, **kwargs) def __setitem__(self,i,y): list.__setitem__(self,i,y) somefunc() def __setslice__(self,i,j,y): list.__setslice__(self,i,j,y) somefunc() >>> a= CaListOfObj([1,2,3]) >>> a[0]=2 Hello There >>> a[1:2]=[4,5] Hello There Is that anything like what you're trying to do? If you want this to work with append and extend you'll have to do the same sort of thing with those. -- http://mail.python.org/mailman/listinfo/python-list