Windows installer: 'precompile standard library' option should pre-compile with -O and -OO

[zware]

BPO	25102
Nosy	@pfmoore, @tjguk, @zware, @zooba
Files	25102_1.patch

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = 'https://github.com/zooba'
closed_at = <Date 2015-09-23.01:24:51.937>
created_at = <Date 2015-09-14.05:01:16.061>
labels = ['type-feature', 'expert-installation', 'OS-windows']
title = "Windows installer: 'precompile standard library' option should pre-compile with -O and -OO"
updated_at = <Date 2015-09-23.01:24:51.936>
user = 'https://github.com/zware'

bugs.python.org fields:

activity = <Date 2015-09-23.01:24:51.936>
actor = 'steve.dower'
assignee = 'steve.dower'
closed = True
closed_date = <Date 2015-09-23.01:24:51.937>
closer = 'steve.dower'
components = ['Installation', 'Windows']
creation = <Date 2015-09-14.05:01:16.061>
creator = 'zach.ware'
dependencies = []
files = ['40466']
hgrepos = []
issue_num = 25102
keywords = ['patch']
message_count = 6.0
messages = ['250625', '250658', '250672', '250684', '250686', '251367']
nosy_count = 5.0
nosy_names = ['paul.moore', 'tim.golden', 'python-dev', 'zach.ware', 'steve.dower']
pr_nums = []
priority = 'low'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue25102'
versions = ['Python 3.5', 'Python 3.6']

[zware]

Since the default all-users install location is now Program Files and thus not world-writable and with the advent of optimization-tagged .pyc files, the 'precompile' option in the installer should also precompile with -O and -OO.

[zooba]

Doesn't it? It's supposed to...

[zware]

It doesn't appear to; my 'C:\Program Files\Python 3.5\Lib\pycache' is full of .pyc's, but none with an optimization tag. To confirm with math rather than eyesight, according to 'dir' there are 168 files in Lib\, and 168 in Lib\pycache rather than the expected 168*3.

For the record, I have not run this Python as a privileged user, so the contents of __pycache__ are not incidental; they were definitely created by the precompile option.

[zooba]

Right, it's just doing the single pass.

You're proposing making a slow part of the install three times slower, correct? Just to confirm :)

[zware]

Steve Dower added the comment:

You're proposing making a slow part of the install three times slower, correct? Just to confirm :)

Indeed I am :). Or extend the precompile options to let the user do whatever of the three they want.

The precompile option is meant as a startup time optimization. -O and -OO are meant as (very slim) runtime optimizations; it only makes sense that people actually concerned enough to use -O/-OO would rather have their startup time optimized as well.

This is pretty low priority, though.

[python-dev]

New changeset 31b230e5517e by Steve Dower in branch '3.5':
Issue bpo-25102: Windows installer does not precompile for -O or -OO.
https://hg.python.org/cpython/rev/31b230e5517e