From d2b5be9a0627e38d2280ef865dab3e74b7d2bde4 Mon Sep 17 00:00:00 2001 From: Christophe Vu-Brugier Date: Wed, 23 Dec 2015 11:46:14 +0100 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 --- Lib/importlib/_bootstrap_external.py | 37 +++++------------------------------- 1 file changed, 5 insertions(+), 32 deletions(-) diff --git a/Lib/importlib/_bootstrap_external.py b/Lib/importlib/_bootstrap_external.py index 616b17f..e30129c 100644 --- a/Lib/importlib/_bootstrap_external.py +++ b/Lib/importlib/_bootstrap_external.py @@ -255,8 +255,6 @@ 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 ' @@ -267,10 +265,7 @@ def cache_from_source(path, debug_override=None, *, optimization=None): optimization = '' if debug_override else 1 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 = '' @@ -281,39 +276,17 @@ def cache_from_source(path, debug_override=None, *, optimization=None): if not optimization.isalnum(): raise ValueError('{!r} is not alphanumeric'.format(optimization)) almost_filename = '{}.{}{}'.format(almost_filename, _OPT, optimization) - return _path_join(head, _PYCACHE, almost_filename + BYTECODE_SUFFIXES[0]) + return _path_join(head, almost_filename + BYTECODE_SUFFIXES[0]) 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') - head, pycache_filename = _path_split(path) - head, pycache = _path_split(head) - if pycache != _PYCACHE: - raise ValueError('{} not bottom-level directory in ' - '{!r}'.format(_PYCACHE, path)) - dot_count = pycache_filename.count('.') - if dot_count not in {2, 3}: - raise ValueError('expected only 2 or 3 dots in ' - '{!r}'.format(pycache_filename)) - elif dot_count == 3: - optimization = pycache_filename.rsplit('.', 2)[-2] - if not optimization.startswith(_OPT): - raise ValueError("optimization portion of filename does not start " - "with {!r}".format(_OPT)) - opt_level = optimization[len(_OPT):] - if not opt_level.isalnum(): - raise ValueError("optimization level {!r} is not an alphanumeric " - "value".format(optimization)) - 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]) -- 2.6.4