From 1153f503a38daf6388021575f1ad6ce8b702911b 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.py | 26 +++++--------------------- 1 file changed, 5 insertions(+), 21 deletions(-) diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py index 5b91c05..a1755ec 100644 --- a/Lib/importlib/_bootstrap.py +++ b/Lib/importlib/_bootstrap.py @@ -444,8 +444,6 @@ def cache_from_source(path, debug_override=None): If debug_override is not None, then it must be a boolean and is used in place of sys.flags.optimize. - If sys.implementation.cache_tag is None then NotImplementedError is raised. - """ debug = not sys.flags.optimize if debug_override is None else debug_override if debug: @@ -454,33 +452,19 @@ def cache_from_source(path, debug_override=None): suffixes = OPTIMIZED_BYTECODE_SUFFIXES 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') - filename = ''.join([(base if base else rest), sep, tag, suffixes[0]]) - return _path_join(head, _PYCACHE, filename) + filename = ''.join([(base if base else rest), suffixes[0]]) + return _path_join(head, filename) def source_from_cache(path): """Given the path to a .pyc./.pyo file, return the path to its .py file. The .pyc/.pyo file does not need to exist; this simply returns the path to - the .py file calculated to correspond to the .pyc/.pyo file. If path does - not conform to PEP 3147 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/.pyo 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)) - if pycache_filename.count('.') != 2: - raise ValueError('expected only 2 dots in ' - '{!r}'.format(pycache_filename)) - 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