Merge part of the trunk changes into the p3yk branch. This merges from 43030
(branch-creation time) up to 43067. 43068 and 43069 contain a little
swapping action between re.py and sre.py, and this mightily confuses svn
merge, so later changes are going in separately.
This merge should break no additional tests.
The last-merged revision is going in a 'last_merge' property on '.' (the
branch directory.) Arbitrarily chosen, really; if there's a BCP for this, I
couldn't find it, but we can easily change it afterwards ;)
diff --git a/Lib/runpy.py b/Lib/runpy.py
new file mode 100755
index 0000000..afb0098
--- /dev/null
+++ b/Lib/runpy.py
@@ -0,0 +1,431 @@
+"""runpy.py - locating and running Python code using the module namespace
+
+Provides support for locating and running Python scripts using the Python
+module namespace instead of the native filesystem.
+
+This allows Python code to play nicely with non-filesystem based PEP 302
+importers when locating support scripts as well as when importing modules.
+"""
+# Written by Nick Coghlan <ncoghlan at gmail.com>
+# to implement PEP 338 (Executing Modules as Scripts)
+
+import sys
+import imp
+
+__all__ = [
+ "run_module",
+]
+
+try:
+ _get_loader = imp.get_loader
+except AttributeError:
+ # get_loader() is not provided by the imp module, so emulate it
+ # as best we can using the PEP 302 import machinery exposed since
+ # Python 2.3. The emulation isn't perfect, but the differences
+ # in the way names are shadowed shouldn't matter in practice.
+ import os.path
+ import marshal # Handle compiled Python files
+
+ # This helper is needed in order for the PEP 302 emulation to
+ # correctly handle compiled files
+ def _read_compiled_file(compiled_file):
+ magic = compiled_file.read(4)
+ if magic != imp.get_magic():
+ return None
+ try:
+ compiled_file.read(4) # Skip timestamp
+ return marshal.load(compiled_file)
+ except Exception:
+ return None
+
+ class _AbsoluteImporter(object):
+ """PEP 302 importer wrapper for top level import machinery"""
+ def find_module(self, mod_name, path=None):
+ if path is not None:
+ return None
+ try:
+ file, filename, mod_info = imp.find_module(mod_name)
+ except ImportError:
+ return None
+ suffix, mode, mod_type = mod_info
+ if mod_type == imp.PY_SOURCE:
+ loader = _SourceFileLoader(mod_name, file,
+ filename, mod_info)
+ elif mod_type == imp.PY_COMPILED:
+ loader = _CompiledFileLoader(mod_name, file,
+ filename, mod_info)
+ elif mod_type == imp.PKG_DIRECTORY:
+ loader = _PackageDirLoader(mod_name, file,
+ filename, mod_info)
+ elif mod_type == imp.C_EXTENSION:
+ loader = _FileSystemLoader(mod_name, file,
+ filename, mod_info)
+ else:
+ loader = _BasicLoader(mod_name, file,
+ filename, mod_info)
+ return loader
+
+
+ class _FileSystemImporter(object):
+ """PEP 302 importer wrapper for filesystem based imports"""
+ def __init__(self, path_item=None):
+ if path_item is not None:
+ if path_item != '' and not os.path.isdir(path_item):
+ raise ImportError("%s is not a directory" % path_item)
+ self.path_dir = path_item
+ else:
+ raise ImportError("Filesystem importer requires "
+ "a directory name")
+
+ def find_module(self, mod_name, path=None):
+ if path is not None:
+ return None
+ path_dir = self.path_dir
+ if path_dir == '':
+ path_dir = os.getcwd()
+ sub_name = mod_name.rsplit(".", 1)[-1]
+ try:
+ file, filename, mod_info = imp.find_module(sub_name,
+ [path_dir])
+ except ImportError:
+ return None
+ if not filename.startswith(path_dir):
+ return None
+ suffix, mode, mod_type = mod_info
+ if mod_type == imp.PY_SOURCE:
+ loader = _SourceFileLoader(mod_name, file,
+ filename, mod_info)
+ elif mod_type == imp.PY_COMPILED:
+ loader = _CompiledFileLoader(mod_name, file,
+ filename, mod_info)
+ elif mod_type == imp.PKG_DIRECTORY:
+ loader = _PackageDirLoader(mod_name, file,
+ filename, mod_info)
+ elif mod_type == imp.C_EXTENSION:
+ loader = _FileSystemLoader(mod_name, file,
+ filename, mod_info)
+ else:
+ loader = _BasicLoader(mod_name, file,
+ filename, mod_info)
+ return loader
+
+
+ class _BasicLoader(object):
+ """PEP 302 loader wrapper for top level import machinery"""
+ def __init__(self, mod_name, file, filename, mod_info):
+ self.mod_name = mod_name
+ self.file = file
+ self.filename = filename
+ self.mod_info = mod_info
+
+ def _fix_name(self, mod_name):
+ if mod_name is None:
+ mod_name = self.mod_name
+ elif mod_name != self.mod_name:
+ raise ImportError("Loader for module %s cannot handle "
+ "module %s" % (self.mod_name, mod_name))
+ return mod_name
+
+ def load_module(self, mod_name=None):
+ mod_name = self._fix_name(mod_name)
+ mod = imp.load_module(mod_name, self.file,
+ self.filename, self.mod_info)
+ mod.__loader__ = self # for introspection
+ return mod
+
+ def get_code(self, mod_name=None):
+ return None
+
+ def get_source(self, mod_name=None):
+ return None
+
+ def is_package(self, mod_name=None):
+ return False
+
+ def close(self):
+ if self.file:
+ self.file.close()
+
+ def __del__(self):
+ self.close()
+
+
+ class _FileSystemLoader(_BasicLoader):
+ """PEP 302 loader wrapper for filesystem based imports"""
+ def get_code(self, mod_name=None):
+ mod_name = self._fix_name(mod_name)
+ return self._get_code(mod_name)
+
+ def get_data(self, pathname):
+ return open(pathname, "rb").read()
+
+ def get_filename(self, mod_name=None):
+ mod_name = self._fix_name(mod_name)
+ return self._get_filename(mod_name)
+
+ def get_source(self, mod_name=None):
+ mod_name = self._fix_name(mod_name)
+ return self._get_source(mod_name)
+
+ def is_package(self, mod_name=None):
+ mod_name = self._fix_name(mod_name)
+ return self._is_package(mod_name)
+
+ def _get_code(self, mod_name):
+ return None
+
+ def _get_filename(self, mod_name):
+ return self.filename
+
+ def _get_source(self, mod_name):
+ return None
+
+ def _is_package(self, mod_name):
+ return False
+
+ class _PackageDirLoader(_FileSystemLoader):
+ """PEP 302 loader wrapper for PKG_DIRECTORY directories"""
+ def _is_package(self, mod_name):
+ return True
+
+
+ class _SourceFileLoader(_FileSystemLoader):
+ """PEP 302 loader wrapper for PY_SOURCE modules"""
+ def _get_code(self, mod_name):
+ return compile(self._get_source(mod_name),
+ self.filename, 'exec')
+
+ def _get_source(self, mod_name):
+ f = self.file
+ f.seek(0)
+ return f.read()
+
+
+ class _CompiledFileLoader(_FileSystemLoader):
+ """PEP 302 loader wrapper for PY_COMPILED modules"""
+ def _get_code(self, mod_name):
+ f = self.file
+ f.seek(0)
+ return _read_compiled_file(f)
+
+
+ def _get_importer(path_item):
+ """Retrieve a PEP 302 importer for the given path item
+
+ The returned importer is cached in sys.path_importer_cache
+ if it was newly created by a path hook.
+
+ If there is no importer, a wrapper around the basic import
+ machinery is returned. This wrapper is never inserted into
+ the importer cache (None is inserted instead).
+
+ The cache (or part of it) can be cleared manually if a
+ rescan of sys.path_hooks is necessary.
+ """
+ try:
+ importer = sys.path_importer_cache[path_item]
+ except KeyError:
+ for path_hook in sys.path_hooks:
+ try:
+ importer = path_hook(path_item)
+ break
+ except ImportError:
+ pass
+ else:
+ importer = None
+ sys.path_importer_cache[path_item] = importer
+ if importer is None:
+ try:
+ importer = _FileSystemImporter(path_item)
+ except ImportError:
+ pass
+ return importer
+
+
+ def _get_path_loader(mod_name, path=None):
+ """Retrieve a PEP 302 loader using a path importer"""
+ if path is None:
+ path = sys.path
+ absolute_loader = _AbsoluteImporter().find_module(mod_name)
+ if isinstance(absolute_loader, _FileSystemLoader):
+ # Found in filesystem, so scan path hooks
+ # before accepting this one as the right one
+ loader = None
+ else:
+ # Not found in filesystem, so use top-level loader
+ loader = absolute_loader
+ else:
+ loader = absolute_loader = None
+ if loader is None:
+ for path_item in path:
+ importer = _get_importer(path_item)
+ if importer is not None:
+ loader = importer.find_module(mod_name)
+ if loader is not None:
+ # Found a loader for our module
+ break
+ else:
+ # No path hook found, so accept the top level loader
+ loader = absolute_loader
+ return loader
+
+ def _get_package(pkg_name):
+ """Retrieve a named package"""
+ pkg = __import__(pkg_name)
+ sub_pkg_names = pkg_name.split(".")
+ for sub_pkg in sub_pkg_names[1:]:
+ pkg = getattr(pkg, sub_pkg)
+ return pkg
+
+ def _get_loader(mod_name, path=None):
+ """Retrieve a PEP 302 loader for the given module or package
+
+ If the module or package is accessible via the normal import
+ mechanism, a wrapper around the relevant part of that machinery
+ is returned.
+
+ Non PEP 302 mechanisms (e.g. the Windows registry) used by the
+ standard import machinery to find files in alternative locations
+ are partially supported, but are searched AFTER sys.path. Normally,
+ these locations are searched BEFORE sys.path, preventing sys.path
+ entries from shadowing them.
+ For this to cause a visible difference in behaviour, there must
+ be a module or package name that is accessible via both sys.path
+ and one of the non PEP 302 file system mechanisms. In this case,
+ the emulation will find the former version, while the builtin
+ import mechanism will find the latter.
+ Items of the following types can be affected by this discrepancy:
+ imp.C_EXTENSION
+ imp.PY_SOURCE
+ imp.PY_COMPILED
+ imp.PKG_DIRECTORY
+ """
+ try:
+ loader = sys.modules[mod_name].__loader__
+ except (KeyError, AttributeError):
+ loader = None
+ if loader is None:
+ imp.acquire_lock()
+ try:
+ # Module not in sys.modules, or uses an unhooked loader
+ parts = mod_name.rsplit(".", 1)
+ if len(parts) == 2:
+ # Sub package, so use parent package's path
+ pkg_name, sub_name = parts
+ if pkg_name and pkg_name[0] != '.':
+ if path is not None:
+ raise ImportError("Path argument must be None "
+ "for a dotted module name")
+ pkg = _get_package(pkg_name)
+ try:
+ path = pkg.__path__
+ except AttributeError:
+ raise ImportError(pkg_name +
+ " is not a package")
+ else:
+ raise ImportError("Relative import syntax is not "
+ "supported by _get_loader()")
+ else:
+ # Top level module, so stick with default path
+ sub_name = mod_name
+
+ for importer in sys.meta_path:
+ loader = importer.find_module(mod_name, path)
+ if loader is not None:
+ # Found a metahook to handle the module
+ break
+ else:
+ # Handling via the standard path mechanism
+ loader = _get_path_loader(mod_name, path)
+ finally:
+ imp.release_lock()
+ return loader
+
+
+# This helper is needed due to a missing component in the PEP 302
+# loader protocol (specifically, "get_filename" is non-standard)
+def _get_filename(loader, mod_name):
+ try:
+ get_filename = loader.get_filename
+ except AttributeError:
+ return None
+ else:
+ return get_filename(mod_name)
+
+# ------------------------------------------------------------
+# Done with the import machinery emulation, on with the code!
+
+def _run_code(code, run_globals, init_globals,
+ mod_name, mod_fname, mod_loader):
+ """Helper for _run_module_code"""
+ if init_globals is not None:
+ run_globals.update(init_globals)
+ run_globals.update(__name__ = mod_name,
+ __file__ = mod_fname,
+ __loader__ = mod_loader)
+ exec code in run_globals
+ return run_globals
+
+def _run_module_code(code, init_globals=None,
+ mod_name=None, mod_fname=None,
+ mod_loader=None, alter_sys=False):
+ """Helper for run_module"""
+ # Set up the top level namespace dictionary
+ if alter_sys:
+ # Modify sys.argv[0] and sys.module[mod_name]
+ temp_module = imp.new_module(mod_name)
+ mod_globals = temp_module.__dict__
+ saved_argv0 = sys.argv[0]
+ restore_module = mod_name in sys.modules
+ if restore_module:
+ saved_module = sys.modules[mod_name]
+ imp.acquire_lock()
+ try:
+ sys.argv[0] = mod_fname
+ sys.modules[mod_name] = temp_module
+ try:
+ _run_code(code, mod_globals, init_globals,
+ mod_name, mod_fname, mod_loader)
+ finally:
+ sys.argv[0] = saved_argv0
+ if restore_module:
+ sys.modules[mod_name] = saved_module
+ else:
+ del sys.modules[mod_name]
+ finally:
+ imp.release_lock()
+ # Copy the globals of the temporary module, as they
+ # may be cleared when the temporary module goes away
+ return mod_globals.copy()
+ else:
+ # Leave the sys module alone
+ return _run_code(code, {}, init_globals,
+ mod_name, mod_fname, mod_loader)
+
+
+def run_module(mod_name, init_globals=None,
+ run_name=None, alter_sys=False):
+ """Execute a module's code without importing it
+
+ Returns the resulting top level namespace dictionary
+ """
+ loader = _get_loader(mod_name)
+ if loader is None:
+ raise ImportError("No module named " + mod_name)
+ code = loader.get_code(mod_name)
+ if code is None:
+ raise ImportError("No code object available for " + mod_name)
+ filename = _get_filename(loader, mod_name)
+ if run_name is None:
+ run_name = mod_name
+ return _run_module_code(code, init_globals, run_name,
+ filename, loader, alter_sys)
+
+
+if __name__ == "__main__":
+ # Run the module specified as the next command line argument
+ if len(sys.argv) < 2:
+ print >> sys.stderr, "No module specified for execution"
+ else:
+ del sys.argv[0] # Make the requested module sys.argv[0]
+ run_module(sys.argv[0], run_name="__main__", alter_sys=True)