counting references to an instance

Brian

Hello;

Is it possible to get an object to return the number of references there
are to itself?

Ex:

class test(object):
pass

a = test()
b = a

# Should print "2", if I knew the name of the method.
print a.refCount()

Many thanks,

Brian.

Jul 18 '05 #1

Thomas Heller

Brian <ba***@sympatico.ca> writes:

Hello;

Is it possible to get an object to return the number of references there
are to itself?

Ex:

class test(object):
pass

a = test()
b = a

# Should print "2", if I knew the name of the method.
print a.refCount()

In Python debug builds, there's the sys.getrefcount() function.

Thomas

Jul 18 '05 #2

Aahz

In article <pa*********************************@sympatico.ca> ,
Brian <ba***@sympatico.ca> wrote:

Is it possible to get an object to return the number of references there
are to itself?

Ex:

class test(object):
pass

a = test()
b = a

# Should print "2", if I knew the name of the method.
print a.refCount()

sys.getrefcount(a) will do the trick -- but it will print 3. Can you
figure out why?
--
Aahz (aa**@pythoncraft.com) <*> http://www.pythoncraft.com/

"The joy of coding Python should be in seeing short, concise, readable
classes that express a lot of action in a small amount of clear code --
not in reams of trivial code that bores the reader to death." --GvR

Jul 18 '05 #3

Brian

On Wed, 04 Feb 2004 14:57:59 -0500, Aahz wrote:

In article <pa*********************************@sympatico.ca> , Brian
<ba***@sympatico.ca> wrote:

Is it possible to get an object to return the number of references there
are to itself?

Ex:

class test(object):
pass

a = test()
b = a

# Should print "2", if I knew the name of the method. print a.refCount()

sys.getrefcount(a) will do the trick -- but it will print 3. Can you
figure out why?

Does the instance of test contain a reference to itself?

Brian.

Jul 18 '05 #4

Aahz

In article <pa*********************************@sympatico.ca> ,
Brian <ba***@sympatico.ca> wrote:

On Wed, 04 Feb 2004 14:57:59 -0500, Aahz wrote:

In article <pa*********************************@sympatico.ca> , Brian
<ba***@sympatico.ca> wrote:

Is it possible to get an object to return the number of references there
are to itself?

Ex:

class test(object):
pass

a = test()
b = a

# Should print "2", if I knew the name of the method. print a.refCount()

sys.getrefcount(a) will do the trick -- but it will print 3. Can you
figure out why?

Does the instance of test contain a reference to itself?

Nope. Robert Brewer's response explained it.
--
Aahz (aa**@pythoncraft.com) <*> http://www.pythoncraft.com/

"The joy of coding Python should be in seeing short, concise, readable
classes that express a lot of action in a small amount of clear code --
not in reams of trivial code that bores the reader to death." --GvR

Jul 18 '05 #5

Michael Hudson

Thomas Heller <th*****@python.net> writes:

Brian <ba***@sympatico.ca> writes:

Hello;

Is it possible to get an object to return the number of references there
are to itself?

Ex:

class test(object):
pass

a = test()
b = a

# Should print "2", if I knew the name of the method.
print a.refCount()

In Python debug builds, there's the sys.getrefcount() function.

In *all* builds, there's sys.getrefcount(). Are you thinking of
sys.gettotalrefcount()?

--
ARTHUR: Yes. It was on display in the bottom of a locked filing
cabinet stuck in a disused lavatory with a sign on the door
saying "Beware of the Leopard".
-- The Hitch-Hikers Guide to the Galaxy, Episode 1

Jul 18 '05 #6

Thomas Heller

Michael Hudson <mw*@python.net> writes:

Thomas Heller <th*****@python.net> writes:

In Python debug builds, there's the sys.getrefcount() function.

In *all* builds, there's sys.getrefcount(). Are you thinking of
sys.gettotalrefcount()?

Yes, probably. Thanks for the correction.

Thomas

Jul 18 '05 #7