Inspecting the Instance Vars in a class/object - How?

[BrendanC]

I'm trying to understand reflection/introspection in Python. How can I
identify the the type of attribute (e.g. instance var) in a class?
The following returns all the class attributes (methods and instance
vars).

However I'm interested in identifying the type of value for each case
- (e.g. I'd like to identify the instance variables separately). (The
Inspect module has an ismethod method, but not an isinstancevaria ble
method).

e.g. In the following example I'd like to extract the class vars
strvar and intNum and ignore the methods/other attribute types.

What is the best way to do this?

class test:
# Dummy Class for reflection testing
strVar = '1234'
intNum = 0

def nullmethod():
pass

def addmethod(self, v1, v2):
v = v1 + v2
return v

if __name__ == "__main__":
mytest = test()
for key in dir(mytest):
value = getattr(object, key)
print 'Key: %s ; Value %s ' % (str(key) ,str(value))

[Diez B. Roggisch]

Re: Inspecting the Instance Vars in a class/object - How?

BrendanC wrote:

I'm trying to understand reflection/introspection in Python. How can I
identify the the type of attribute (e.g. instance var) in a class?
The following returns all the class attributes (methods and instance
vars).
>
However I'm interested in identifying the type of value for each case
- (e.g. I'd like to identify the instance variables separately). (The
Inspect module has an ismethod method, but not an isinstancevaria ble
method).

Because there is no such thing, as it is not a *type*. It's a question on
where the value is stored.

Every *instance* has a dictionary holding it's data. You can normally access
it using __dict__.

But it's not "pure" in the sense that only the variables you created
yourself are contained. It also contains the reference to the class.

On the class, there is also a __dict__, which contains the
method-descriptors and class-variables.

In the face of multi-inheritance, things get even more complicated, as then
the values are acquired through MRO-lookup.

e.g. In the following example I'd like to extract the class vars
strvar and intNum and ignore the methods/other attribute types.
>
What is the best way to do this?
>
class test:
# Dummy Class for reflection testing
strVar = '1234'
intNum = 0
>
def nullmethod():
pass
>
def addmethod(self, v1, v2):
v = v1 + v2
return v
>
if __name__ == "__main__":
mytest = test()
for key in dir(mytest):
value = getattr(object, key)
print 'Key: %s ; Value %s ' % (str(key) ,str(value))

if name in mytest.__dict__ :
print "instance variable"