|  | extended setattr() | | |
| | | Rotlaus |  |
|  Posted: Mon Jul 07, 2008 6:01 am Post subject: extended setattr() |  |
2 weeks ago i asked for a etended getattr() which worked really fine,
but now i would love to have a extended setattr() as well.
Lets assume i have some classes:
class A(object):
def __init__(self):
self.B = B()
class B(object):
def __init__(self):
self.C = C()
class C(object):
def __init__(self, foo='', bar=''):
self.foo = foo
self.bar = bar
and now i wanna do something like this:
a=A()
ext_setattr(a, 'B.C', ('a', 'b'))
Is this possible? It would also be nice if the attributes would be
created if they not exist, always implying that
objectname==objecttype.
Kind regards,
Andre |
| |
| | | Diez B. Roggisch | |
| | Posted: Tue Jul 08, 2008 4:29 am Post subject: Re: extended setattr() | |
Rotlaus schrieb:
| Quote: | On 7 Jul., 08:01, Rotlaus <rotl...@gmail.com> wrote:
2 weeks ago i asked for a etended getattr() which worked really fine,
but now i would love to have a extendedsetattr() as well.
I've tried the following, but it doesn't work:
class A(object):
def __init__(self):
self.B = B()
class B(object):
def __init__(self):
self.C = C('foo')
class C(object):
def __init__(self, txt=''):
self.txt = txt
def ext_setattr(obj, attr, val):
for subattr in attr.split("."):
obj = getattr(obj, subattr)
obj = val
import test
a = A()
Traceback (most recent call last):
File "<stdin>", line 1, in <module
NameError: name 'A' is not defined
a = test.A()
a.B.C.txt
'foo'
ext_setattr(a, 'B.C.txt', 'bar')
a.B.C.txt
'foo'
What am i doing wrong?
|
obj = val won't work.
You need to use a setattr(obj, name, val)
on the last attribute-name.
Diez |
| |
| | | Rotlaus | |
| | Posted: Tue Jul 08, 2008 6:27 am Post subject: Re: extended setattr() | |
On 7 Jul., 08:01, Rotlaus <rotl...@gmail.com> wrote:
| Quote: | 2 weeks ago i asked for a etended getattr() which worked really fine,
but now i would love to have a extendedsetattr() as well.
|
I've tried the following, but it doesn't work:
class A(object):
def __init__(self):
self.B = B()
class B(object):
def __init__(self):
self.C = C('foo')
class C(object):
def __init__(self, txt=''):
self.txt = txt
def ext_setattr(obj, attr, val):
for subattr in attr.split("."):
obj = getattr(obj, subattr)
obj = val
| Quote: | import test
a = A()
Traceback (most recent call last): |
File "<stdin>", line 1, in <module>
NameError: name 'A' is not defined
| Quote: | a = test.A()
a.B.C.txt
'foo'
ext_setattr(a, 'B.C.txt', 'bar')
a.B.C.txt
'foo' |
What am i doing wrong? |
| |
| | | Andre Adrian | |
| | Posted: Tue Jul 08, 2008 10:59 am Post subject: Re: extended setattr() | |
Diez B. Roggisch <deets <at> nospam.web.de> writes:
| Quote: | def ext_setattr(obj, attr, val):
for subattr in attr.split("."):
obj = getattr(obj, subattr)
obj = val
import test
a = A()
Traceback (most recent call last):
File "<stdin>", line 1, in <module
NameError: name 'A' is not defined
a = test.A()
a.B.C.txt
'foo'
ext_setattr(a, 'B.C.txt', 'bar')
a.B.C.txt
'foo'
What am i doing wrong?
obj = val won't work.
|
Why is this so? Shouldn't it be the same?
| Quote: | You need to use a setattr(obj, name, val)
on the last attribute-name.
|
Ok, so this works:
def ext_setattr(obj, attr, val):
attributes = attr.split('.')
for subattr in attributes[:-1]:
obj = getattr(obj, subattr)
setattr(obj, attributes[-1], val) |
| |
| | | Diez B. Roggisch | |
| | Posted: Tue Jul 08, 2008 3:25 pm Post subject: Re: extended setattr() | |
Andre Adrian wrote:
| Quote: | Diez B. Roggisch <deets <at> nospam.web.de> writes:
def ext_setattr(obj, attr, val):
for subattr in attr.split("."):
obj = getattr(obj, subattr)
obj = val
import test
a = A()
Traceback (most recent call last):
File "<stdin>", line 1, in <module
NameError: name 'A' is not defined
a = test.A()
a.B.C.txt
'foo'
ext_setattr(a, 'B.C.txt', 'bar')
a.B.C.txt
'foo'
What am i doing wrong?
obj = val won't work.
Why is this so? Shouldn't it be the same?
|
No, of course not!
obj = val
binds the object reffered to by val to the LOCAL name obj. That's python
101, make sure you get variables/names and scopes proper.
| Quote: | You need to use a setattr(obj, name, val)
on the last attribute-name.
Ok, so this works:
def ext_setattr(obj, attr, val):
attributes = attr.split('.')
for subattr in attributes[:-1]:
obj = getattr(obj, subattr)
setattr(obj, attributes[-1], val)
|
Yep.
Diez |
| |
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