On Fri, Apr 4, 2008 at 2:49 AM, Zaur Shibzoukhov <[EMAIL PROTECTED]> wrote:
> I suggest a context manager for property defining/redefining. There is a
> prototype and illustrative example:
>
>
>
> --------------------------------------------------------------------------------------------------------------
> import sys
>
> null = object()
> _property = property
> class property(_property):
> #
> def __init__(self, *args, **kw):
> _property.__init__(self, *args, **kw)
> self.__enter__ = self.__enter
> self.__exit__ = self.__exit
> #
> @classmethod
> def __enter__(self):
> return null
> #
> @classmethod
> def __exit__(self, type, value, tb):
> if tb is None:
> frame = sys._getframe(1)
> self.__exitHandler(self, frame.f_locals)
> #
> def __enter(self):
> return null
> #
> def __exit(self, type, value, tb):
> if tb is None:
> frame = sys._getframe(1)
> self.__exitHandler(self, frame.f_locals)
> #
> @staticmethod
> def __exitHandler(self, _locals):
> propName = "_"
> PropName = str(id(self))
> for key, value in _locals.items():
> if value is null:
> propName = key
> PropName = key.capitalize()
> break
>
> if type(self) == type(property):
> getFunc = _locals.pop('get', None)
> setFunc = _locals.pop('set', None)
> delFunc = _locals.pop('delete', None)
> doc = _locals.pop('doc', None)
> else:
> getFunc = _locals.pop('get', None) or self.fget
> setFunc = _locals.pop('set', None) or self.fset
> delFunc = _locals.pop('delete', None) or self.fdel
> doc = _locals.pop('doc', None) or self.__doc__
>
> if getFunc:
> funcName = "_get"+PropName
> getFunc.__name__ = funcName
> _locals[funcName] = getFunc
> if setFunc:
> funcName = "_set"+PropName
> setFunc.__name__ = funcName
> _locals[funcName] = setFunc
> if delFunc:
> funcName = "_del"+PropName
> delFunc.__name__ = funcName
> _locals[funcName] = delFunc
>
> prop = property(getFunc, setFunc, delFunc)
> prop.__doc__ = doc
> _locals[propName] = prop
>
>
> -----------------------------------------------------------------------------------------------------------
>
> def testPropertyMaker():
> class AAA:
> _v = 1
> with property as v:
> doc = "Example of making property with *with* statement"
> def get(self):
> return self._v
> def set(self, v):
> self._v = v
>
> class BBB(AAA):
> with AAA.v as v:
> doc = "Example of modified property"
> def get(self):
> return [self._v]
>
> a=AAA()
> a.v = 10
> print(a.v)
> print(AAA.v.__doc__)
>
> b=BBB()
> b.v = 100
> print(b.v)
> print(BBB.v.__doc__)
>
> This code is also in attachment.
>
> Is it suitable for contextlib.py?
I don't really see how this is better/easier than:
class AAA:
def get_x(): pass
def set_x(): pass
x = property(get_x, set_x, None, "The x property")
>
>
>
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>
>
--
Cheers,
Benjamin Peterson
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