WANG Cong wrote:
On 06/25/10 15:34, Bruno Desthuilliers
<bruno.42.desthuilli...@websiteburo.invalid> wrote:
WANG Cong a écrit :
Hi, list!
I have a doubt about the design of dynamic attribute creation by
assignments in Python.
As we know, in Python, we are able to create a new attribute of
a class dynamically by an assignment:
class test: pass
...
test.a = "hello"
test.a
'hello'
However, I still don't get the points why Python designs it like this.
My points are:
(snip)
Python's classes are plain objects, and like any other object are
created at runtime. Having to special-case them would break the
simplicity and uniformity of Python for no good reason. Just like
there's no good reason to make setattr() working differently for class
and non-class objects.
For implementaiton, perhaps, but not for the language design, how could
a language design be perfect if we can use setattr() like assignments
while use other things, e.g. delattr(), not? Is there any way to express
delattr() as simple as expressing setattr() with assignments? I doubt...
>>> del test.a
>>> test.a
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: class test has no attribute 'a'
Looks pretty simple to me...
~Ethan~
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