Hi David,
On 05/02/11 08:01 PM, David Burton wrote:
**
*
*
*..., I have noticed that pygame events are somewhat weird. They are
objects, but they don't always behave like proper Python objects.
There's no __dict__ attribute, and dir() doesn't work, which I find
annoying:*
Python 3.1.3 (r313:86834, Nov 27 2010, 18:30:53) [MSC v.1500 32 bit
(Intel)] on win32
Type "copyright", "credits" or "license()" for more information.
>>> import pygame
>>> ev = pygame.event.Event( pygame.USEREVENT, {'id':'test',
'internal':False} )
>>> dir(ev)
[]
>>> ev.__dict__
Traceback (most recent call last):
File "<pyshell#6>", line 1, in <module>
ev.__dict__
AttributeError: event member not defined
>>> ev.type
24
>>> ev.id <http://ev.id>
'test'
>>> ev.internal
False
>>> repr(ev)
"<Event(24-UserEvent {'internal': False, 'id': 'test'})>"
>>>
*Contrast that with how other Python objects behave:*
>>> class junk:
fee = 1
fie = True
foe = 'giant'
fum = (1,2,3)
>>> j1 = junk()
>>> repr(j1)
'<__main__.junk object at 0x034FA870>'
>>> dir(j1)
['__class__', '__delattr__', '__dict__', '__doc__', '__eq__',
'__format__', '__ge__', '__getattribute__', '__gt__', '__hash__',
'__init__', '__le__', '__lt__', '__module__', '__ne__', '__new__',
'__reduce__', '__reduce_ex__', '__repr__', '__setattr__',
'__sizeof__', '__str__', '__subclasshook__', '__weakref__', 'fee',
'fie', 'foe', 'fum']
*See what I mean? With other Python objects, it is easy to enumerate
the attributes of an object. But it is not obvious how to do that for
pygame event objects (though repr() somehow manages it).*
*
*
*Does anyone know how repr() manages to find the attributes for the
pygame event, since dir() doesn't work?*
*
*
Pygame predates Python 2.2, when types became classes. I suppose the
Event type was never updated. Also, the Event attributes may be
read-only intentionally. I don't know for sure. If you are requesting a
__dict__ for Event types I will add an issue to the Pygame tracker at
Motherhamster and have a look. Even if system generated events need to
keep their attributes immutable, I see no problem with mutable attibutes
on user generated events.
repr() uses a different mechanism from Python attribute access, a
separate tp slot function. This function directly accesses the event's
dictionary at C level, even when it is hidden from dir() at the Python
level.
Lenard Lindstrom
