From e2ea659eac1849db471d3c01a0d0af9d6fca2e9a Mon Sep 17 00:00:00 2001
From: Christophe Vu-Brugier <cvubrugier@fastmail.fm>
Date: Wed, 22 Feb 2017 16:48:49 -0800
Subject: [PATCH] Add importlib fix for PEP 3147 issue
Python 3 has a new standard for installing .pyc file, called PEP
3147. Unfortunately, this standard requires both the .py and .pyc
files to be installed for a Python module to be found. This is quite
annoying on space-constrained embedded systems, since the .py file is
technically not required for execution.
This patch changes cache_from_source() and source_from_cache() in
importlib to get rid of the "__pycache__" directory.
This effectively disables PEP 3147 for:
* The python standard library
* Packages built with distutils or setuptools
* Packages built with automake that use the `py-compile` helper
Signed-off-by: Christophe Vu-Brugier <cvubrugier@fastmail.fm>
[ Andrey Smirnov: ported to Python 3.6 ]
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
Lib/importlib/_bootstrap_external.py | 44 ++++------------------------
1 file changed, 5 insertions(+), 39 deletions(-)
diff --git a/Lib/importlib/_bootstrap_external.py b/Lib/importlib/_bootstrap_external.py
index 25a3f8c0e0..2cb9a9aa52 100644
--- a/Lib/importlib/_bootstrap_external.py
+++ b/Lib/importlib/_bootstrap_external.py
@@ -313,8 +313,6 @@ def cache_from_source(path, debug_override=None, *, optimization=None):
a True value is the same as setting 'optimization' to the empty string
while a False value is equivalent to setting 'optimization' to '1'.
- If sys.implementation.cache_tag is None then NotImplementedError is raised.
-
"""
if debug_override is not None:
_warnings.warn('the debug_override parameter is deprecated; use '
@@ -326,10 +324,7 @@ def cache_from_source(path, debug_override=None, *, optimization=None):
path = _os.fspath(path)
head, tail = _path_split(path)
base, sep, rest = tail.rpartition('.')
- tag = sys.implementation.cache_tag
- if tag is None:
- raise NotImplementedError('sys.implementation.cache_tag is None')
- almost_filename = ''.join([(base if base else rest), sep, tag])
+ almost_filename = ''.join([(base if base else rest)])
if optimization is None:
if sys.flags.optimize == 0:
optimization = ''
@@ -366,46 +361,17 @@ def cache_from_source(path, debug_override=None, *, optimization=None):
head.lstrip(path_separators),
filename,
)
- return _path_join(head, _PYCACHE, filename)
+ return _path_join(head, filename)
def source_from_cache(path):
"""Given the path to a .pyc. file, return the path to its .py file.
The .pyc file does not need to exist; this simply returns the path to
- the .py file calculated to correspond to the .pyc file. If path does
- not conform to PEP 3147/488 format, ValueError will be raised. If
- sys.implementation.cache_tag is None then NotImplementedError is raised.
-
+ the .py file calculated to correspond to the .pyc file.
"""
- if sys.implementation.cache_tag is None:
- raise NotImplementedError('sys.implementation.cache_tag is None')
- path = _os.fspath(path)
- head, pycache_filename = _path_split(path)
- found_in_pycache_prefix = False
- if sys.pycache_prefix is not None:
- stripped_path = sys.pycache_prefix.rstrip(path_separators)
- if head.startswith(stripped_path + path_sep):
- head = head[len(stripped_path):]
- found_in_pycache_prefix = True
- if not found_in_pycache_prefix:
- head, pycache = _path_split(head)
- if pycache != _PYCACHE:
- raise ValueError(f'{_PYCACHE} not bottom-level directory in '
- f'{path!r}')
- dot_count = pycache_filename.count('.')
- if dot_count not in {2, 3}:
- raise ValueError(f'expected only 2 or 3 dots in {pycache_filename!r}')
- elif dot_count == 3:
- optimization = pycache_filename.rsplit('.', 2)[-2]
- if not optimization.startswith(_OPT):
- raise ValueError("optimization portion of filename does not start "
- f"with {_OPT!r}")
- opt_level = optimization[len(_OPT):]
- if not opt_level.isalnum():
- raise ValueError(f"optimization level {optimization!r} is not an "
- "alphanumeric value")
- base_filename = pycache_filename.partition('.')[0]
+ head, filename = _path_split(path)
+ base_filename = filename.partition('.')[0]
return _path_join(head, base_filename + SOURCE_SUFFIXES[0])
--
2.25.1