In the attached example I show that there's a significant memory overhead present whenever a pre-compiled pyc is not present.

This only occurs with more than 5225 objects (dictionaries in this case)
allocated. At 13756 objects, the mysterious pyc overhead is 50% of memory
usage.

I've reproduced this issue in python 2.6, 2.7, 3.4. I imagine it's present in all cpythons.


$ python -c 'import repro'
16736
$ python -c 'import repro'
8964
$ python -c 'import repro'
8964

$ rm *.pyc; python -c 'import repro'
16740
$ rm *.pyc; python -c 'import repro'
16736
$ rm *.pyc; python -c 'import repro'
16740