python27_output.txt

# Python 2.7.13 build with pytracemalloc patches applied.
$ python27_tracemalloc test-pickle-tracemalloc.py
Python version info: 2.7.13 (default, Jun 25 2018, 22:08:02)
[GCC 4.2.1 Compatible Apple LLVM 9.1.0 (clang-902.0.39.2)]
            Baseline (Tot:    0.0 MiB, Inc:    0.0 MiB)
        Data created (Tot:  200.0 MiB, Inc:  200.0 MiB)
       Pickle dumped (Tot:  246.0 MiB, Inc:   46.0 MiB)
$ python27_tracemalloc test-pickle-tracemalloc.py load
Python version info: 2.7.13 (default, Jun 25 2018, 22:08:02)
[GCC 4.2.1 Compatible Apple LLVM 9.1.0 (clang-902.0.39.2)]
            Baseline (Tot:    0.0 MiB, Inc:    0.0 MiB)
       Pickle loaded (Tot:  199.0 MiB, Inc:  199.0 MiB)

python36_output.txt

$ python3.6 test-pickle-tracemalloc.py
Python version info: 3.6.5 (default, May  7 2018, 16:43:32)
[GCC 4.2.1 Compatible Apple LLVM 9.1.0 (clang-902.0.39.1)]
            Baseline (Tot:    0.0 MiB, Inc:    0.0 MiB)
        Data created (Tot:  200.0 MiB, Inc:  200.0 MiB)
       Pickle dumped (Tot:  246.0 MiB, Inc:   46.0 MiB)
$ python3.6 test-pickle-tracemalloc.py load
Python version info: 3.6.5 (default, May  7 2018, 16:43:32)
[GCC 4.2.1 Compatible Apple LLVM 9.1.0 (clang-902.0.39.1)]
            Baseline (Tot:    0.0 MiB, Inc:    0.0 MiB)
       Pickle loaded (Tot:  199.6 MiB, Inc:  199.6 MiB)

test-pickle-tracemalloc.py

from __future__ import print_function
import tracemalloc
import pickle
import random
from string import ascii_uppercase

try:
    # Python 2 compatibility
    range = xrange
    try:
        # use the optimised version, in Py2 this requires an explicit import
        import cPickle as pickle
    except ImportError:
        pass
except NameError:
    pass


last = None
def display_memory_change(msg):
    global last
    snap = tracemalloc.take_snapshot()
    statdiff, last = snap.compare_to(last, 'filename', True), snap
    tot = sum(s.size for s in statdiff)
    change = sum(s.size_diff for s in statdiff)
    print('{:>20} (Tot: {:6.1f} MiB, Inc: {:6.1f} MiB)'.format(
        msg, tot / 2 ** 20, change / 2 ** 20))


def random_string(_c=random.choice, _l=ascii_uppercase):
    return "".join([_c(_l) for _ in range(20)])


def create_file():
    # use locals for faster looping
    rfloat, rstring, rrange = random.random, random_string, random.randrange
    x = [(rfloat(), rstring(), rrange(2 ** 64)) for _ in range(1000000)]
    display_memory_change('Data created')

    pickle.dump(x, open('machin.pkl', 'wb'))
    display_memory_change('Pickle dumped')


def load_file():
    y = pickle.load(open('machin.pkl', 'rb'))
    display_memory_change('Pickle loaded')
    return y


if __name__=="__main__":
    import sys
    print('Python version info:', sys.version)
    tracemalloc.start()
    last = tracemalloc.take_snapshot()
    display_memory_change('Baseline')
    if 'load' not in sys.argv:
        create_file()
    else:
        load_file()