Kevac Marko a écrit :
On Nov 10, 8:39 pm, Marc 'BlackJack' Rintsch [EMAIL PROTECTED] wrote:
Don't think so. It's a surprise for many but then class attributes are
not that common in code or they even use this gotcha for
immutable default values. As long a the value isn't changed the default
Donn Ingle a écrit :
(about class attributes, instance attributes and lookup rules)
Okay, I sort of see that. It's not a property
For clarity, better s/property/attribute/ here. In Python, property is a
builtin class used for computed attributes.
of 'j' so it looks upwards
into the class.
Kevac Marko [EMAIL PROTECTED] writes:
When changing default value, is there any way to change class
attribute and all referenced attributes too?
class M:
name = uMarko
a, b = M(), M()
a.name = uKevac
print M.name, a.name, b.name
- Marko Kevac Marko
Is there any way to get
On Nov 10, 8:39 pm, Marc 'BlackJack' Rintsch [EMAIL PROTECTED] wrote:
Don't think so. It's a surprise for many but then class attributes are
not that common in code or they even use this gotcha for
immutable default values. As long a the value isn't changed the default
value is just
Kevac Marko [EMAIL PROTECTED] writes:
When changing default value, is there any way to change class
attribute and all referenced attributes too?
class M:
name = uMarko
a, b = M(), M()
a.name = uKevac
print M.name, a.name, b.name
- Marko Kevac Marko
Is there any way to get here -
Very interesting reply. I must ask a few questions, interleaved:
If you mean that all instances of Class Canvas and Thing will share
the *same* Stack, I think we can do it kind of like this:
What's the difference between same Stack and same instance of Stack? I
thought I knew what an instance
Donn Ingle a écrit :
(snip)
I have been hearing about new classes for a while but there's no clarity
in the Python docs (that I can find).
Then you perhaps should have a closer look at the entries in the
'documentation' sub-menu of python.org !-)
Anyway, here's a direct link:
On 11 10 , 10 01 , Donn Ingle [EMAIL PROTECTED] wrote:
def pop(self):
item = self.list[-1]
del self.list[-1]
return item
Is there some reason you do all that and not a self.list.pop(0)?
Hi.
There are no special reasons I do it that way.
Just not familiar
On 11 10 , 5 48 , Donn Ingle [EMAIL PROTECTED] wrote:
## == API in another module perhaps ===
Class Stack:
def push(self,stuff):
pass
Class Canvas:
def do(self):
s.push(data) #I don't feel right about 's' here.
Class Thing:
def buzz(self):
print s.pop(0)
## == User space
Very interesting reply. I must ask a few questions, interleaved:
If you mean that all instances of Class Canvas and Thing will share
the *same* Stack, I think we can do it kind of like this:
What's the difference between same Stack and same instance of Stack? I
thought I knew what an instance
Donn Ingle [EMAIL PROTECTED] wrote:
class Stack:
list = []
Okay, this has me a little weirded-out. How is this different from
putting it in:
def __init__(self):
self.list = []
?
I see from tests that it is different, but I don't quite grok it. Who
owns the list ref?
The
The first creates an attribute of the class, the second creates an
attribute in the instance.
Given that, can you clarify this:
class Test:
attribute = original value
class Bob:
def __init__(self):
self.ref = Test()
class Jim:
def __init__(self):
On Sat, 10 Nov 2007 17:00:13 +0200, Donn Ingle wrote:
The first creates an attribute of the class, the second creates an
attribute in the instance.
Given that, can you clarify this:
class Test:
attribute = original value
class Bob:
def __init__(self):
self.ref =
Included again for clarity:
class Test:
attribute = original value
class Bob:
def __init__(self):
self.ref = Test()
class Jim:
def __init__(self):
self.ref = Test()
b = Bob()
j = Jim()
print b.ref.attribute #prints original value
On Sat, 10 Nov 2007 18:53:08 +0200, Donn Ingle wrote:
Included again for clarity:
class Test:
attribute = original value
class Bob:
def __init__(self):
self.ref = Test()
class Jim:
def __init__(self):
self.ref = Test()
b = Bob()
j =
Thanks for your time and patience Marc, that was some hotshot ascii art.
I'll have to take some time to digest this.
\d
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On Sat, 10 Nov 2007 17:39:04 +, Marc 'BlackJack' Rintsch wrote:
On Sat, 10 Nov 2007 18:53:08 +0200, Donn Ingle wrote:
print b.ref.attribute # print haschanged
print j.ref.attribute #prints original value
## If it changed and an attribute of the Class, then
## why is it back to original
Hi,
I'm getting myself really confused. I have three classes. Two of them need
to reference the third, like so:
Canvas --- Stack --- Thing
I am doing this right now:
s = Stack()
And then within class Canvas: I am referring directly to the global
variable 's' (and again from Thing).
Now, this
Donn Ingle a écrit :
Hi,
I'm getting myself really confused. I have three classes. Two of them need
to reference the third, like so:
Canvas --- Stack --- Thing
I am doing this right now:
s = Stack()
And then within class Canvas: I am referring directly to the global
variable 's'
I thought this might be a case for multiple inheritance
???
Well, in terms of having Canvas and Thing inherit from Stack and thereby
(somehow, not sure how) they would both have access to Stack.stack (a list)
wrt/ all Thing instances having to refer to a same Stack instance,
there's a pretty
Donn Ingle a écrit :
I thought this might be a case for multiple inheritance
???
Well, in terms of having Canvas and Thing inherit from Stack and thereby
(somehow, not sure how) they would both have access to Stack.stack (a list)
wrt/ all Thing instances having to refer to a same Stack
I guess you mean instances, not classes.
Yes.
Err...Perhaps a dumb question, but what about passing the common
objects to initializers ?
s = Stack()
c = Canvas(s)
t = Thing(s)
Okay, I see where you're going. It's better than what I have at the moment.
Thanks.
\d
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