On Sat, Apr 17, 2021 at 1:38 PM Guido van Rossum
I'm not going to report results, but we could use mypy itself as an example real-world code base. Mypy is almost 100% annotated. It does not include `from __future__ import annotations` lines but those could easily be added mechanically for some experiment.
ISTM that the unmarshal times reported by Inada are largely proportional to the code size numbers, so perhaps the following three-way experiment would give an indication:
(1) Addthe sizes of all pyc files for mypy run with Python 3.9 (classic) (2) Ditto run with Python 3.10a7 (PEP 563) (3) Ditto run with Larry's branch (PEP 649, assuming it's on by default there -- otherwise, modify the source by inserting the needed future import at the top)
Please don't use 3.10a7, but latest master branch. CFG optimizer broke some PEP 563 optimization and I fixed it yesterday. https://github.com/python/cpython/pull/25419
The repo is github.com/python/mypy, the subdirectory to look is mypy, WITH THE EXCLUSION OF THE typeshed SUBDIRECTORY THEREOF.
I want to measure import time and memory usage. Will `import mypy.main` import all important modules? This is my quick result of (1) and (2). I can not try (3) because of memory error. (see later). ## memory usage ``` $ cat a.py import tracemalloc tracemalloc.start() import mypy.main print("memory:", tracemalloc.get_traced_memory()[0]) # (1) $ python3 a.py memory: 8963137 $ python3 -OO a.py memory: 8272848 # (2) $ ~/local/python-dev/bin/python3 a.py memory: 8849216 $ ~/local/python-dev/bin/python3 -OO a.py memory: 8104730
(8963137-8849216)/8963137 0.012709947421310196 (8272848-8104730)/8272848 0.020321659481716575
PEP 563 saved 1~2% memory.
## GC time
$ pyperf timeit -s 'import mypy.main, gc' -- 'gc.collect()' 3.9: ..................... 2.68 ms +- 0.02 ms 3.10: ..................... 2.23 ms +- 0.01 ms Mean +- std dev: [3.9] 2.68 ms +- 0.02 ms -> [3.10] 2.23 ms +- 0.01 ms: 1.20x faster ``` PEP 563 is 1.2x faster! ## import time ``` $ python3 -m pyperf command python3 -c 'import mypy.main' (1) command: Mean +- std dev: 99.6 ms +- 0.3 ms (2) command: Mean +- std dev: 93.3 ms +- 1.2 ms
(99.6-93.3)/99.6 0.06325301204819275
PEP 563 reduced 6% importtime.
## memory error on co_annotations
I modifled py_compile to add `from __future__ import co_annotations`
automatically.
$ ../co_annotations/python -m compileall mypy
Listing 'mypy'...
Compiling 'mypy/checker.py'...
free(): corrupted unsorted chunks
Aborted
#0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#1 0x00007ffff7c73859 in __GI_abort () at abort.c:79
#2 0x00007ffff7cde3ee in __libc_message
(action=action@entry=do_abort, fmt=fmt@entry=0x7ffff7e08285 "%s\n") at
../sysdeps/posix/libc_fatal.c:155
#3 0x00007ffff7ce647c in malloc_printerr
(str=str@entry=0x7ffff7e0a718 "free(): corrupted unsorted chunks") at
malloc.c:5347
#4 0x00007ffff7ce81c2 in _int_free (av=0x7ffff7e39b80