mirror of
https://github.com/python/cpython.git
synced 2025-11-02 22:51:25 +00:00
583 lines
20 KiB
Python
583 lines
20 KiB
Python
"""Utilities to support packages."""
|
|
|
|
# NOTE: This module must remain compatible with Python 2.3, as it is shared
|
|
# by setuptools for distribution with Python 2.3 and up.
|
|
|
|
import os
|
|
import sys
|
|
import imp
|
|
import os.path
|
|
from types import ModuleType
|
|
|
|
__all__ = [
|
|
'get_importer', 'iter_importers', 'get_loader', 'find_loader',
|
|
'walk_packages', 'iter_modules',
|
|
'ImpImporter', 'ImpLoader', 'read_code', 'extend_path',
|
|
]
|
|
|
|
def read_code(stream):
|
|
# This helper is needed in order for the PEP 302 emulation to
|
|
# correctly handle compiled files
|
|
import marshal
|
|
|
|
magic = stream.read(4)
|
|
if magic != imp.get_magic():
|
|
return None
|
|
|
|
stream.read(4) # Skip timestamp
|
|
return marshal.load(stream)
|
|
|
|
|
|
def simplegeneric(func):
|
|
"""Make a trivial single-dispatch generic function"""
|
|
registry = {}
|
|
def wrapper(*args, **kw):
|
|
ob = args[0]
|
|
try:
|
|
cls = ob.__class__
|
|
except AttributeError:
|
|
cls = type(ob)
|
|
try:
|
|
mro = cls.__mro__
|
|
except AttributeError:
|
|
try:
|
|
class cls(cls, object):
|
|
pass
|
|
mro = cls.__mro__[1:]
|
|
except TypeError:
|
|
mro = object, # must be an ExtensionClass or some such :(
|
|
for t in mro:
|
|
if t in registry:
|
|
return registry[t](*args, **kw)
|
|
else:
|
|
return func(*args, **kw)
|
|
try:
|
|
wrapper.__name__ = func.__name__
|
|
except (TypeError, AttributeError):
|
|
pass # Python 2.3 doesn't allow functions to be renamed
|
|
|
|
def register(typ, func=None):
|
|
if func is None:
|
|
return lambda f: register(typ, f)
|
|
registry[typ] = func
|
|
return func
|
|
|
|
wrapper.__dict__ = func.__dict__
|
|
wrapper.__doc__ = func.__doc__
|
|
wrapper.register = register
|
|
return wrapper
|
|
|
|
|
|
def walk_packages(path=None, prefix='', onerror=None):
|
|
"""Yields (module_loader, name, ispkg) for all modules recursively
|
|
on path, or, if path is None, all accessible modules.
|
|
|
|
'path' should be either None or a list of paths to look for
|
|
modules in.
|
|
|
|
'prefix' is a string to output on the front of every module name
|
|
on output.
|
|
|
|
Note that this function must import all *packages* (NOT all
|
|
modules!) on the given path, in order to access the __path__
|
|
attribute to find submodules.
|
|
|
|
'onerror' is a function which gets called with one argument (the
|
|
name of the package which was being imported) if any exception
|
|
occurs while trying to import a package. If no onerror function is
|
|
supplied, ImportErrors are caught and ignored, while all other
|
|
exceptions are propagated, terminating the search.
|
|
|
|
Examples:
|
|
|
|
# list all modules python can access
|
|
walk_packages()
|
|
|
|
# list all submodules of ctypes
|
|
walk_packages(ctypes.__path__, ctypes.__name__+'.')
|
|
"""
|
|
|
|
def seen(p, m={}):
|
|
if p in m:
|
|
return True
|
|
m[p] = True
|
|
|
|
for importer, name, ispkg in iter_modules(path, prefix):
|
|
yield importer, name, ispkg
|
|
|
|
if ispkg:
|
|
try:
|
|
__import__(name)
|
|
except ImportError:
|
|
if onerror is not None:
|
|
onerror(name)
|
|
except Exception:
|
|
if onerror is not None:
|
|
onerror(name)
|
|
else:
|
|
raise
|
|
else:
|
|
path = getattr(sys.modules[name], '__path__', None) or []
|
|
|
|
# don't traverse path items we've seen before
|
|
path = [p for p in path if not seen(p)]
|
|
|
|
for item in walk_packages(path, name+'.', onerror):
|
|
yield item
|
|
|
|
|
|
def iter_modules(path=None, prefix=''):
|
|
"""Yields (module_loader, name, ispkg) for all submodules on path,
|
|
or, if path is None, all top-level modules on sys.path.
|
|
|
|
'path' should be either None or a list of paths to look for
|
|
modules in.
|
|
|
|
'prefix' is a string to output on the front of every module name
|
|
on output.
|
|
"""
|
|
|
|
if path is None:
|
|
importers = iter_importers()
|
|
else:
|
|
importers = map(get_importer, path)
|
|
|
|
yielded = {}
|
|
for i in importers:
|
|
for name, ispkg in iter_importer_modules(i, prefix):
|
|
if name not in yielded:
|
|
yielded[name] = 1
|
|
yield i, name, ispkg
|
|
|
|
|
|
#@simplegeneric
|
|
def iter_importer_modules(importer, prefix=''):
|
|
if not hasattr(importer, 'iter_modules'):
|
|
return []
|
|
return importer.iter_modules(prefix)
|
|
|
|
iter_importer_modules = simplegeneric(iter_importer_modules)
|
|
|
|
|
|
class ImpImporter:
|
|
"""PEP 302 Importer that wraps Python's "classic" import algorithm
|
|
|
|
ImpImporter(dirname) produces a PEP 302 importer that searches that
|
|
directory. ImpImporter(None) produces a PEP 302 importer that searches
|
|
the current sys.path, plus any modules that are frozen or built-in.
|
|
|
|
Note that ImpImporter does not currently support being used by placement
|
|
on sys.meta_path.
|
|
"""
|
|
|
|
def __init__(self, path=None):
|
|
self.path = path
|
|
|
|
def find_module(self, fullname, path=None):
|
|
# Note: we ignore 'path' argument since it is only used via meta_path
|
|
subname = fullname.split(".")[-1]
|
|
if subname != fullname and self.path is None:
|
|
return None
|
|
if self.path is None:
|
|
path = None
|
|
else:
|
|
path = [os.path.realpath(self.path)]
|
|
try:
|
|
file, filename, etc = imp.find_module(subname, path)
|
|
except ImportError:
|
|
return None
|
|
return ImpLoader(fullname, file, filename, etc)
|
|
|
|
def iter_modules(self, prefix=''):
|
|
if self.path is None or not os.path.isdir(self.path):
|
|
return
|
|
|
|
yielded = {}
|
|
import inspect
|
|
|
|
filenames = os.listdir(self.path)
|
|
filenames.sort() # handle packages before same-named modules
|
|
|
|
for fn in filenames:
|
|
modname = inspect.getmodulename(fn)
|
|
if modname=='__init__' or modname in yielded:
|
|
continue
|
|
|
|
path = os.path.join(self.path, fn)
|
|
ispkg = False
|
|
|
|
if not modname and os.path.isdir(path) and '.' not in fn:
|
|
modname = fn
|
|
for fn in os.listdir(path):
|
|
subname = inspect.getmodulename(fn)
|
|
if subname=='__init__':
|
|
ispkg = True
|
|
break
|
|
else:
|
|
continue # not a package
|
|
|
|
if modname and '.' not in modname:
|
|
yielded[modname] = 1
|
|
yield prefix + modname, ispkg
|
|
|
|
|
|
class ImpLoader:
|
|
"""PEP 302 Loader that wraps Python's "classic" import algorithm
|
|
"""
|
|
code = source = None
|
|
|
|
def __init__(self, fullname, file, filename, etc):
|
|
self.file = file
|
|
self.filename = filename
|
|
self.fullname = fullname
|
|
self.etc = etc
|
|
|
|
def load_module(self, fullname):
|
|
self._reopen()
|
|
try:
|
|
mod = imp.load_module(fullname, self.file, self.filename, self.etc)
|
|
finally:
|
|
if self.file:
|
|
self.file.close()
|
|
# Note: we don't set __loader__ because we want the module to look
|
|
# normal; i.e. this is just a wrapper for standard import machinery
|
|
return mod
|
|
|
|
def get_data(self, pathname):
|
|
return open(pathname, "rb").read()
|
|
|
|
def _reopen(self):
|
|
if self.file and self.file.closed:
|
|
mod_type = self.etc[2]
|
|
if mod_type==imp.PY_SOURCE:
|
|
self.file = open(self.filename, 'rU')
|
|
elif mod_type in (imp.PY_COMPILED, imp.C_EXTENSION):
|
|
self.file = open(self.filename, 'rb')
|
|
|
|
def _fix_name(self, fullname):
|
|
if fullname is None:
|
|
fullname = self.fullname
|
|
elif fullname != self.fullname:
|
|
raise ImportError("Loader for module %s cannot handle "
|
|
"module %s" % (self.fullname, fullname))
|
|
return fullname
|
|
|
|
def is_package(self, fullname):
|
|
fullname = self._fix_name(fullname)
|
|
return self.etc[2]==imp.PKG_DIRECTORY
|
|
|
|
def get_code(self, fullname=None):
|
|
fullname = self._fix_name(fullname)
|
|
if self.code is None:
|
|
mod_type = self.etc[2]
|
|
if mod_type==imp.PY_SOURCE:
|
|
source = self.get_source(fullname)
|
|
self.code = compile(source, self.filename, 'exec')
|
|
elif mod_type==imp.PY_COMPILED:
|
|
self._reopen()
|
|
try:
|
|
self.code = read_code(self.file)
|
|
finally:
|
|
self.file.close()
|
|
elif mod_type==imp.PKG_DIRECTORY:
|
|
self.code = self._get_delegate().get_code()
|
|
return self.code
|
|
|
|
def get_source(self, fullname=None):
|
|
fullname = self._fix_name(fullname)
|
|
if self.source is None:
|
|
mod_type = self.etc[2]
|
|
if mod_type==imp.PY_SOURCE:
|
|
self._reopen()
|
|
try:
|
|
self.source = self.file.read()
|
|
finally:
|
|
self.file.close()
|
|
elif mod_type==imp.PY_COMPILED:
|
|
if os.path.exists(self.filename[:-1]):
|
|
f = open(self.filename[:-1], 'rU')
|
|
self.source = f.read()
|
|
f.close()
|
|
elif mod_type==imp.PKG_DIRECTORY:
|
|
self.source = self._get_delegate().get_source()
|
|
return self.source
|
|
|
|
|
|
def _get_delegate(self):
|
|
return ImpImporter(self.filename).find_module('__init__')
|
|
|
|
def get_filename(self, fullname=None):
|
|
fullname = self._fix_name(fullname)
|
|
mod_type = self.etc[2]
|
|
if self.etc[2]==imp.PKG_DIRECTORY:
|
|
return self._get_delegate().get_filename()
|
|
elif self.etc[2] in (imp.PY_SOURCE, imp.PY_COMPILED, imp.C_EXTENSION):
|
|
return self.filename
|
|
return None
|
|
|
|
|
|
try:
|
|
import zipimport
|
|
from zipimport import zipimporter
|
|
|
|
def iter_zipimport_modules(importer, prefix=''):
|
|
dirlist = zipimport._zip_directory_cache[importer.archive].keys()
|
|
dirlist.sort()
|
|
_prefix = importer.prefix
|
|
plen = len(_prefix)
|
|
yielded = {}
|
|
import inspect
|
|
for fn in dirlist:
|
|
if not fn.startswith(_prefix):
|
|
continue
|
|
|
|
fn = fn[plen:].split(os.sep)
|
|
|
|
if len(fn)==2 and fn[1].startswith('__init__.py'):
|
|
if fn[0] not in yielded:
|
|
yielded[fn[0]] = 1
|
|
yield fn[0], True
|
|
|
|
if len(fn)!=1:
|
|
continue
|
|
|
|
modname = inspect.getmodulename(fn[0])
|
|
if modname=='__init__':
|
|
continue
|
|
|
|
if modname and '.' not in modname and modname not in yielded:
|
|
yielded[modname] = 1
|
|
yield prefix + modname, False
|
|
|
|
iter_importer_modules.register(zipimporter, iter_zipimport_modules)
|
|
|
|
except ImportError:
|
|
pass
|
|
|
|
|
|
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.setdefault(path_item, importer)
|
|
|
|
if importer is None:
|
|
try:
|
|
importer = ImpImporter(path_item)
|
|
except ImportError:
|
|
importer = None
|
|
return importer
|
|
|
|
|
|
def iter_importers(fullname=""):
|
|
"""Yield PEP 302 importers for the given module name
|
|
|
|
If fullname contains a '.', the importers will be for the package
|
|
containing fullname, otherwise they will be importers for sys.meta_path,
|
|
sys.path, and Python's "classic" import machinery, in that order. If
|
|
the named module is in a package, that package is imported as a side
|
|
effect of invoking this function.
|
|
|
|
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
|
|
"""
|
|
if fullname.startswith('.'):
|
|
raise ImportError("Relative module names not supported")
|
|
if '.' in fullname:
|
|
# Get the containing package's __path__
|
|
pkg = '.'.join(fullname.split('.')[:-1])
|
|
if pkg not in sys.modules:
|
|
__import__(pkg)
|
|
path = getattr(sys.modules[pkg], '__path__', None) or []
|
|
else:
|
|
for importer in sys.meta_path:
|
|
yield importer
|
|
path = sys.path
|
|
for item in path:
|
|
yield get_importer(item)
|
|
if '.' not in fullname:
|
|
yield ImpImporter()
|
|
|
|
def get_loader(module_or_name):
|
|
"""Get a PEP 302 "loader" object for module_or_name
|
|
|
|
If the module or package is accessible via the normal import
|
|
mechanism, a wrapper around the relevant part of that machinery
|
|
is returned. Returns None if the module cannot be found or imported.
|
|
If the named module is not already imported, its containing package
|
|
(if any) is imported, in order to establish the package __path__.
|
|
|
|
This function uses iter_importers(), and is thus subject to the same
|
|
limitations regarding platform-specific special import locations such
|
|
as the Windows registry.
|
|
"""
|
|
if module_or_name in sys.modules:
|
|
module_or_name = sys.modules[module_or_name]
|
|
if isinstance(module_or_name, ModuleType):
|
|
module = module_or_name
|
|
loader = getattr(module, '__loader__', None)
|
|
if loader is not None:
|
|
return loader
|
|
fullname = module.__name__
|
|
else:
|
|
fullname = module_or_name
|
|
return find_loader(fullname)
|
|
|
|
def find_loader(fullname):
|
|
"""Find a PEP 302 "loader" object for fullname
|
|
|
|
If fullname contains dots, path must be the containing package's __path__.
|
|
Returns None if the module cannot be found or imported. This function uses
|
|
iter_importers(), and is thus subject to the same limitations regarding
|
|
platform-specific special import locations such as the Windows registry.
|
|
"""
|
|
for importer in iter_importers(fullname):
|
|
loader = importer.find_module(fullname)
|
|
if loader is not None:
|
|
return loader
|
|
|
|
return None
|
|
|
|
|
|
def extend_path(path, name):
|
|
"""Extend a package's path.
|
|
|
|
Intended use is to place the following code in a package's __init__.py:
|
|
|
|
from pkgutil import extend_path
|
|
__path__ = extend_path(__path__, __name__)
|
|
|
|
This will add to the package's __path__ all subdirectories of
|
|
directories on sys.path named after the package. This is useful
|
|
if one wants to distribute different parts of a single logical
|
|
package as multiple directories.
|
|
|
|
It also looks for *.pkg files beginning where * matches the name
|
|
argument. This feature is similar to *.pth files (see site.py),
|
|
except that it doesn't special-case lines starting with 'import'.
|
|
A *.pkg file is trusted at face value: apart from checking for
|
|
duplicates, all entries found in a *.pkg file are added to the
|
|
path, regardless of whether they are exist the filesystem. (This
|
|
is a feature.)
|
|
|
|
If the input path is not a list (as is the case for frozen
|
|
packages) it is returned unchanged. The input path is not
|
|
modified; an extended copy is returned. Items are only appended
|
|
to the copy at the end.
|
|
|
|
It is assumed that sys.path is a sequence. Items of sys.path that
|
|
are not (unicode or 8-bit) strings referring to existing
|
|
directories are ignored. Unicode items of sys.path that cause
|
|
errors when used as filenames may cause this function to raise an
|
|
exception (in line with os.path.isdir() behavior).
|
|
"""
|
|
|
|
if not isinstance(path, list):
|
|
# This could happen e.g. when this is called from inside a
|
|
# frozen package. Return the path unchanged in that case.
|
|
return path
|
|
|
|
pname = os.path.join(*name.split('.')) # Reconstitute as relative path
|
|
# Just in case os.extsep != '.'
|
|
sname = os.extsep.join(name.split('.'))
|
|
sname_pkg = sname + os.extsep + "pkg"
|
|
init_py = "__init__" + os.extsep + "py"
|
|
|
|
path = path[:] # Start with a copy of the existing path
|
|
|
|
for dir in sys.path:
|
|
if not isinstance(dir, basestring) or not os.path.isdir(dir):
|
|
continue
|
|
subdir = os.path.join(dir, pname)
|
|
# XXX This may still add duplicate entries to path on
|
|
# case-insensitive filesystems
|
|
initfile = os.path.join(subdir, init_py)
|
|
if subdir not in path and os.path.isfile(initfile):
|
|
path.append(subdir)
|
|
# XXX Is this the right thing for subpackages like zope.app?
|
|
# It looks for a file named "zope.app.pkg"
|
|
pkgfile = os.path.join(dir, sname_pkg)
|
|
if os.path.isfile(pkgfile):
|
|
try:
|
|
f = open(pkgfile)
|
|
except IOError, msg:
|
|
sys.stderr.write("Can't open %s: %s\n" %
|
|
(pkgfile, msg))
|
|
else:
|
|
for line in f:
|
|
line = line.rstrip('\n')
|
|
if not line or line.startswith('#'):
|
|
continue
|
|
path.append(line) # Don't check for existence!
|
|
f.close()
|
|
|
|
return path
|
|
|
|
def get_data(package, resource):
|
|
"""Get a resource from a package.
|
|
|
|
This is a wrapper round the PEP 302 loader get_data API. The package
|
|
argument should be the name of a package, in standard module format
|
|
(foo.bar). The resource argument should be in the form of a relative
|
|
filename, using '/' as the path separator. The parent directory name '..'
|
|
is not allowed, and nor is a rooted name (starting with a '/').
|
|
|
|
The function returns a binary string, which is the contents of the
|
|
specified resource.
|
|
|
|
For packages located in the filesystem, which have already been imported,
|
|
this is the rough equivalent of
|
|
|
|
d = os.path.dirname(sys.modules[package].__file__)
|
|
data = open(os.path.join(d, resource), 'rb').read()
|
|
|
|
If the package cannot be located or loaded, or it uses a PEP 302 loader
|
|
which does not support get_data(), then None is returned.
|
|
"""
|
|
|
|
loader = get_loader(package)
|
|
if loader is None or not hasattr(loader, 'get_data'):
|
|
return None
|
|
mod = sys.modules.get(package) or loader.load_module(package)
|
|
if mod is None or not hasattr(mod, '__file__'):
|
|
return None
|
|
|
|
# Modify the resource name to be compatible with the loader.get_data
|
|
# signature - an os.path format "filename" starting with the dirname of
|
|
# the package's __file__
|
|
parts = resource.split('/')
|
|
parts.insert(0, os.path.dirname(mod.__file__))
|
|
resource_name = os.path.join(*parts)
|
|
return loader.get_data(resource_name)
|