On Mon, 25 Oct 2010 09:39:47 +1000, James Mills wrote: > On Mon, Oct 25, 2010 at 9:21 AM, chad <cdal...@gmail.com> wrote: >> I just saw this technique used in python script that was/is used to >> automatically log them in myspace.com. Hence the question. > > Function/Method Chaining is probably used a lot in Python itself: > >>>> x = 4 >>>> x.__add__(1).__sub__(3) > 2 > > The implementation of many common operators return self (the object > you're working with).
I can't think of any operations on built-ins that return self, except in the special case of an identity operation. And even then, it's not common: >>> x = 2.5 >>> y = x.__add__(1) >>> y is x False >>> y = x.__add__(0) >>> y is x False Ah wait, no, I thought of one: __iadd__: >>> x = [2.5] >>> y = x.__iadd__([None]) >>> y is x True But: >>> x = 2.5 >>> y = x.__iadd__(1) Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: 'float' object has no attribute '__iadd__' By the way, in case any newbies out there are reading... ...if you're writing x.__add__(1).__sub__(3) instead of x + 1 - 3 then you're almost certainly doing it wrong. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
