class AutoSlots(type):
def __new__(cls, name, bases, dct):
slots = dict.fromkeys(dct.get('__slots__', []))
if '__init__' in dct:
init = dct['__init__']
ifvn = init.func_code.co_varnames
for i in xrange(init.func_code.co_argcount):
x = ifvn[i]
if x[:1] == '_':
slots[x[1:]] = None
dct['__slots__'] = slots.keys()
return type.__new__(cls, name, bases, dct)
def InitAttrs(ob, args):
for k, v in args.iteritems():
if k[:1] == '_':
setattr(ob,k[1:],v)
'''
If you would like to automatically assign arguments to methods
to the attributes of an object, you can do so by prefixing those
local variable names with a a single leading underscore '_',
which will be stripped from the instance variable (_x becomes x).
class Foo(object):
def __init__(self, _x, _y, _z):
InitAttrs(self, locals())
#...
AutoSlots further allows you to automatically generate __slots__
for your classes, pulling the variables which need to be slots
from the arguments to the __init__ method on your class.
class Goo(object):
__metaclass__ = AutoSlots
def __init__(self, _x, _y, _z):
InitAttrs(self, locals())
#...
>>> x = Goo(1,2,3)
>>> [i for i in dir(x) if i[:1] != '_']
['x', 'y', 'z']
>>> x.a = 7
Traceback (most recent call last):
File "<stdin>", line 1, in ?
AttributeError: 'Goo' object has no attribute 'a'
>>>
'''
