[egenix-users] Calc size of Python objects

[M.-A. Lemburg]

Dirk Holtwick wrote:
> So this one would be more accurate? If I understand you right, it's not 
> possible to calculate the exact amount of memory used by a python object?
> 
> class myPyObject:
>     pass
> 
> def calcsize(i, s=0):
>     s = sizeof(i)
>     if type(i) == type({}):
>         for k, v in i.items():
>             s += calcsize(k)
>             s += calcsize(v)
>             s += 2 * sizeof(myPyObject())

Well, the table size will usually be around 3/2 of the number
of entries. For more details see the C implementation :-)

>     elif type(i) == type([]):
>         for v in i:
>             s += calcsize(v)
>             s += 1 * sizeof(myPyObject())
>     elif type(i) == type((1,)):
>         for v in i:
>             s += calcsize(v)
>     return s
> 
> I don't know exctly how to determine the size of a PyObject.

import struct
sizeof_PyObject = len(struct.pack('P', 0))

On 32-bit machines that's usually 4 bytes.

> The proc.py is exactly what I was looking for and it's working fine. 
> Thanks a lot Marc-Andre! Helps me tracking down some strange memory bugs 
> in my application.

-- 
Marc-Andre Lemburg
CEO eGenix.com Software GmbH
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