24-01-2010, 00:38:29 Terry Reedy <tjre...@udel.edu> wrote:
On 1/23/2010 10:56 AM, Arnaud Delobelle wrote:
thinke365<thinke...@gmail.com> writes:
for example, i may define a python class:
class A:
def sayHello():
print 'hello'
a = A()
a.attr1 = 'hello'
a.attr2 = 'bb'
b = A()
a.attr2 = 'aa'
how can i know whether an object have an attribute named attr1?
hasattr(a, 'attr1')
or
try: a.attr1
except AttributeError: pass
or
-- if you are interested only in attributes contained by attributes dict
of this particular object (and no in attributes of its type, base types
nor attributes calculated on-demand by __getattr__/__getattribute__
methods) --
you can check its __dict__ --
* using vars(), e.g.: if 'attr1' in vars(a)...
* or directly (less elegant?), e.g.: if 'attr1' in a.__dict__...
But please remember that it doesn't work for instances of types with
__slots__ defined (see:
http://docs.python.org/reference/datamodel.html#slots).
Regards,
*j
--
Jan Kaliszewski (zuo) <z...@chopin.edu.pl>
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