PySizeof: almost useful

[Ian Leitch]

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Hi list,

I'm writing a little module to calculate the size of given objects, I
just need a few little pointers to get the thing into a useful shape.

Code here: http://dev.gentoo.org/~port001/Code/PySizeof/

The points I'm confused about are:

1. My method of determining the malloc() overhead is probably laughable,
what's the correct method?

2. I'm at a loss as how to calculate the size of a long object -- any tips?

3. How much memory do instance, module and instancemethod objects hold?
You'll notice I'm getting the size of most objects internal structures,
what structures' size should I be measuring for such objects?

4. When calculating the size of a dict, if it contains more than the
initial ma_smalltable size (8) should I be subtracting 8 from the len()
number multiplied with the size of a dict entry? See line 73 in pysizeof.py

No doubt there are some other glaring mistakes :)

Many thanks to anyone bored enough to review this code.

- -- Ian
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[Alex Martelli]

Ian Leitch <po*****@gentoo.org> wrote:
...

2. I'm at a loss as how to calculate the size of a long object -- any tips?
#include "longintrepr.h" (from the Python sources). Then, given a
PyLongObject *l, abs(l->ob_size) is the number of "digits", each taking
SHIFT bits.
Many thanks to anyone bored enough to review this code.

Sorry, I don't have the time, but I hope the above tip can be useful.
Alex

[MrJean1]

Check the sizeof() method in the mxTools package from eGenix:

<http://www.egenix.com/files/python/mxTools.html>

/Jean Brouwers