Assigning the module's __class__ means you can otherwise initialize your
module instance normally--all your class needs to do is declare your
properties or magic methods. If you overwrite the sys.modules entry for
your module with a new instance of a custom subclass, all your module
initialization needs to be done within--or propagated to--the new class
or instance.
//arry/
On 09/08/2017 01:45 PM, Ethan Furman wrote:
On 09/08/2017 12:44 PM, Larry Hastings wrote:
I've updated PEP 549 with a new title--"Instance Descriptors" is a
better name than "Instance Properties"--and to
clarify my rationale for the PEP. I've also updated the prototype
with code cleanups and a new type:
"collections.abc.InstanceDescriptor", a base class that allows user
classes to be instance descriptors.
I like the new title, I'm +0 on the PEP itself, and I have one
correction for the PEP: we've had the ability to simulate module
properties for ages:
Python 2.7.6 (default, Oct 26 2016, 20:32:47)
[GCC 4.8.4] on linux2
Type "help", "copyright", "credits" or "license" for more
information.
--> import module_class
--> module_class.hello
'hello'
--> module_class.hello = 'hola'
--> module_class.hello
'hola'
And the code:
class ModuleClass(object):
@property
def hello(self):
try:
return self._greeting
except AttributeError:
return 'hello'
@hello.setter
def hello(self, value):
self._greeting = value
import sys
sys.modules[__name__] = ModuleClass()
I will admit I don't see what reassigning the __class__ attribute on a
module did for us.
--
~Ethan~
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