diff options
Diffstat (limited to 'Lib/importlib/_bootstrap.py')
| -rw-r--r-- | Lib/importlib/_bootstrap.py | 38 |
1 files changed, 33 insertions, 5 deletions
diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py index 857f308f86..a4eab474ca 100644 --- a/Lib/importlib/_bootstrap.py +++ b/Lib/importlib/_bootstrap.py @@ -9,7 +9,7 @@ work. One should use importlib as the public-facing version of this module. # # IMPORTANT: Whenever making changes to this module, be sure to run # a top-level make in order to get the frozen version of the module -# update. Not doing so, will result in the Makefile to fail for +# update. Not doing so will result in the Makefile to fail for # all others who don't have a ./python around to freeze the module # in the early stages of compilation. # @@ -20,10 +20,6 @@ work. One should use importlib as the public-facing version of this module. # reference any injected objects! This includes not only global code but also # anything specified at the class level. -# XXX Make sure all public names have no single leading underscore and all -# others do. - - # Bootstrap-related code ###################################################### _CASE_INSENSITIVE_PLATFORMS = 'win', 'cygwin', 'darwin' @@ -498,6 +494,38 @@ def _verbose_message(message, *args, verbosity=1): print(message.format(*args), file=sys.stderr) +class ModuleManager: + + """Context manager which returns the module to be loaded. + + Does the proper unloading from sys.modules upon failure. + + """ + + def __init__(self, name): + self._name = name + + def __enter__(self): + self._module = sys.modules.get(self._name) + self._is_reload = self._module is not None + if not self._is_reload: + # This must be done before open() is called as the 'io' module + # implicitly imports 'locale' and would otherwise trigger an + # infinite loop. + self._module = new_module(self._name) + # This must be done before putting the module in sys.modules + # (otherwise an optimization shortcut in import.c becomes wrong) + self._module.__initializing__ = True + sys.modules[self._name] = self._module + return self._module + + def __exit__(self, *args): + self._module.__initializing__ = False + del self._module + if any(arg is not None for arg in args) and not self._is_reload: + del sys.modules[self._name] + + def set_package(fxn): """Set __package__ on the returned module.""" def set_package_wrapper(*args, **kwargs): |