mirror of
https://github.com/python/cpython.git
synced 2024-11-27 23:47:29 +01:00
d6e83fbf30
Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM> Co-authored-by: Brett Cannon <brett@python.org> Co-authored-by: Oleg Iarygin <oleg@arhadthedev.net>
530 lines
18 KiB
Python
530 lines
18 KiB
Python
"""Utilities to support packages."""
|
|
|
|
from collections import namedtuple
|
|
from functools import singledispatch as simplegeneric
|
|
import importlib
|
|
import importlib.util
|
|
import importlib.machinery
|
|
import os
|
|
import os.path
|
|
import sys
|
|
from types import ModuleType
|
|
import warnings
|
|
|
|
__all__ = [
|
|
'get_importer', 'iter_importers', 'get_loader', 'find_loader',
|
|
'walk_packages', 'iter_modules', 'get_data',
|
|
'read_code', 'extend_path',
|
|
'ModuleInfo',
|
|
]
|
|
|
|
|
|
ModuleInfo = namedtuple('ModuleInfo', 'module_finder name ispkg')
|
|
ModuleInfo.__doc__ = 'A namedtuple with minimal info about a module.'
|
|
|
|
|
|
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 != importlib.util.MAGIC_NUMBER:
|
|
return None
|
|
|
|
stream.read(12) # Skip rest of the header
|
|
return marshal.load(stream)
|
|
|
|
|
|
def walk_packages(path=None, prefix='', onerror=None):
|
|
"""Yields ModuleInfo 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 info in iter_modules(path, prefix):
|
|
yield info
|
|
|
|
if info.ispkg:
|
|
try:
|
|
__import__(info.name)
|
|
except ImportError:
|
|
if onerror is not None:
|
|
onerror(info.name)
|
|
except Exception:
|
|
if onerror is not None:
|
|
onerror(info.name)
|
|
else:
|
|
raise
|
|
else:
|
|
path = getattr(sys.modules[info.name], '__path__', None) or []
|
|
|
|
# don't traverse path items we've seen before
|
|
path = [p for p in path if not seen(p)]
|
|
|
|
yield from walk_packages(path, info.name+'.', onerror)
|
|
|
|
|
|
def iter_modules(path=None, prefix=''):
|
|
"""Yields ModuleInfo 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()
|
|
elif isinstance(path, str):
|
|
raise ValueError("path must be None or list of paths to look for "
|
|
"modules in")
|
|
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 ModuleInfo(i, name, ispkg)
|
|
|
|
|
|
@simplegeneric
|
|
def iter_importer_modules(importer, prefix=''):
|
|
if not hasattr(importer, 'iter_modules'):
|
|
return []
|
|
return importer.iter_modules(prefix)
|
|
|
|
|
|
# Implement a file walker for the normal importlib path hook
|
|
def _iter_file_finder_modules(importer, prefix=''):
|
|
if importer.path is None or not os.path.isdir(importer.path):
|
|
return
|
|
|
|
yielded = {}
|
|
import inspect
|
|
try:
|
|
filenames = os.listdir(importer.path)
|
|
except OSError:
|
|
# ignore unreadable directories like import does
|
|
filenames = []
|
|
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(importer.path, fn)
|
|
ispkg = False
|
|
|
|
if not modname and os.path.isdir(path) and '.' not in fn:
|
|
modname = fn
|
|
try:
|
|
dircontents = os.listdir(path)
|
|
except OSError:
|
|
# ignore unreadable directories like import does
|
|
dircontents = []
|
|
for fn in dircontents:
|
|
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
|
|
|
|
iter_importer_modules.register(
|
|
importlib.machinery.FileFinder, _iter_file_finder_modules)
|
|
|
|
|
|
try:
|
|
import zipimport
|
|
from zipimport import zipimporter
|
|
|
|
def iter_zipimport_modules(importer, prefix=''):
|
|
dirlist = sorted(zipimport._zip_directory_cache[importer.archive])
|
|
_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 prefix + 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 finder for the given path item
|
|
|
|
The returned finder is cached in sys.path_importer_cache
|
|
if it was newly created by a path hook.
|
|
|
|
The cache (or part of it) can be cleared manually if a
|
|
rescan of sys.path_hooks is necessary.
|
|
"""
|
|
path_item = os.fsdecode(path_item)
|
|
try:
|
|
importer = sys.path_importer_cache[path_item]
|
|
except KeyError:
|
|
for path_hook in sys.path_hooks:
|
|
try:
|
|
importer = path_hook(path_item)
|
|
sys.path_importer_cache.setdefault(path_item, importer)
|
|
break
|
|
except ImportError:
|
|
pass
|
|
else:
|
|
importer = None
|
|
return importer
|
|
|
|
|
|
def iter_importers(fullname=""):
|
|
"""Yield finders for the given module name
|
|
|
|
If fullname contains a '.', the finders will be for the package
|
|
containing fullname, otherwise they will be all registered top level
|
|
finders (i.e. those on both sys.meta_path and sys.path_hooks).
|
|
|
|
If the named module is in a package, that package is imported as a side
|
|
effect of invoking this function.
|
|
|
|
If no module name is specified, all top level finders are produced.
|
|
"""
|
|
if fullname.startswith('.'):
|
|
msg = "Relative module name {!r} not supported".format(fullname)
|
|
raise ImportError(msg)
|
|
if '.' in fullname:
|
|
# Get the containing package's __path__
|
|
pkg_name = fullname.rpartition(".")[0]
|
|
pkg = importlib.import_module(pkg_name)
|
|
path = getattr(pkg, '__path__', None)
|
|
if path is None:
|
|
return
|
|
else:
|
|
yield from sys.meta_path
|
|
path = sys.path
|
|
for item in path:
|
|
yield get_importer(item)
|
|
|
|
|
|
def get_loader(module_or_name):
|
|
"""Get a "loader" object for module_or_name
|
|
|
|
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__.
|
|
"""
|
|
warnings._deprecated("pkgutil.get_loader",
|
|
f"{warnings._DEPRECATED_MSG}; "
|
|
"use importlib.util.find_spec() instead",
|
|
remove=(3, 14))
|
|
if module_or_name in sys.modules:
|
|
module_or_name = sys.modules[module_or_name]
|
|
if module_or_name is None:
|
|
return None
|
|
if isinstance(module_or_name, ModuleType):
|
|
module = module_or_name
|
|
loader = getattr(module, '__loader__', None)
|
|
if loader is not None:
|
|
return loader
|
|
if getattr(module, '__spec__', None) is None:
|
|
return None
|
|
fullname = module.__name__
|
|
else:
|
|
fullname = module_or_name
|
|
return find_loader(fullname)
|
|
|
|
|
|
def find_loader(fullname):
|
|
"""Find a "loader" object for fullname
|
|
|
|
This is a backwards compatibility wrapper around
|
|
importlib.util.find_spec that converts most failures to ImportError
|
|
and only returns the loader rather than the full spec
|
|
"""
|
|
warnings._deprecated("pkgutil.find_loader",
|
|
f"{warnings._DEPRECATED_MSG}; "
|
|
"use importlib.util.find_spec() instead",
|
|
remove=(3, 14))
|
|
if fullname.startswith('.'):
|
|
msg = "Relative module name {!r} not supported".format(fullname)
|
|
raise ImportError(msg)
|
|
try:
|
|
spec = importlib.util.find_spec(fullname)
|
|
except (ImportError, AttributeError, TypeError, ValueError) as ex:
|
|
# This hack fixes an impedance mismatch between pkgutil and
|
|
# importlib, where the latter raises other errors for cases where
|
|
# pkgutil previously raised ImportError
|
|
msg = "Error while finding loader for {!r} ({}: {})"
|
|
raise ImportError(msg.format(fullname, type(ex), ex)) from ex
|
|
return spec.loader if spec is not None else 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__)
|
|
|
|
For each directory on sys.path that has a subdirectory that
|
|
matches the package name, add the subdirectory to the package's
|
|
__path__. 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
|
|
|
|
sname_pkg = name + ".pkg"
|
|
|
|
path = path[:] # Start with a copy of the existing path
|
|
|
|
parent_package, _, final_name = name.rpartition('.')
|
|
if parent_package:
|
|
try:
|
|
search_path = sys.modules[parent_package].__path__
|
|
except (KeyError, AttributeError):
|
|
# We can't do anything: find_loader() returns None when
|
|
# passed a dotted name.
|
|
return path
|
|
else:
|
|
search_path = sys.path
|
|
|
|
for dir in search_path:
|
|
if not isinstance(dir, str):
|
|
continue
|
|
|
|
finder = get_importer(dir)
|
|
if finder is not None:
|
|
portions = []
|
|
if hasattr(finder, 'find_spec'):
|
|
spec = finder.find_spec(final_name)
|
|
if spec is not None:
|
|
portions = spec.submodule_search_locations or []
|
|
# Is this finder PEP 420 compliant?
|
|
elif hasattr(finder, 'find_loader'):
|
|
_, portions = finder.find_loader(final_name)
|
|
|
|
for portion in portions:
|
|
# XXX This may still add duplicate entries to path on
|
|
# case-insensitive filesystems
|
|
if portion not in path:
|
|
path.append(portion)
|
|
|
|
# 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 OSError as msg:
|
|
sys.stderr.write("Can't open %s: %s\n" %
|
|
(pkgfile, msg))
|
|
else:
|
|
with f:
|
|
for line in f:
|
|
line = line.rstrip('\n')
|
|
if not line or line.startswith('#'):
|
|
continue
|
|
path.append(line) # Don't check for existence!
|
|
|
|
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.
|
|
"""
|
|
|
|
spec = importlib.util.find_spec(package)
|
|
if spec is None:
|
|
return None
|
|
loader = spec.loader
|
|
if loader is None or not hasattr(loader, 'get_data'):
|
|
return None
|
|
# XXX needs test
|
|
mod = (sys.modules.get(package) or
|
|
importlib._bootstrap._load(spec))
|
|
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)
|
|
|
|
|
|
_NAME_PATTERN = None
|
|
|
|
def resolve_name(name):
|
|
"""
|
|
Resolve a name to an object.
|
|
|
|
It is expected that `name` will be a string in one of the following
|
|
formats, where W is shorthand for a valid Python identifier and dot stands
|
|
for a literal period in these pseudo-regexes:
|
|
|
|
W(.W)*
|
|
W(.W)*:(W(.W)*)?
|
|
|
|
The first form is intended for backward compatibility only. It assumes that
|
|
some part of the dotted name is a package, and the rest is an object
|
|
somewhere within that package, possibly nested inside other objects.
|
|
Because the place where the package stops and the object hierarchy starts
|
|
can't be inferred by inspection, repeated attempts to import must be done
|
|
with this form.
|
|
|
|
In the second form, the caller makes the division point clear through the
|
|
provision of a single colon: the dotted name to the left of the colon is a
|
|
package to be imported, and the dotted name to the right is the object
|
|
hierarchy within that package. Only one import is needed in this form. If
|
|
it ends with the colon, then a module object is returned.
|
|
|
|
The function will return an object (which might be a module), or raise one
|
|
of the following exceptions:
|
|
|
|
ValueError - if `name` isn't in a recognised format
|
|
ImportError - if an import failed when it shouldn't have
|
|
AttributeError - if a failure occurred when traversing the object hierarchy
|
|
within the imported package to get to the desired object.
|
|
"""
|
|
global _NAME_PATTERN
|
|
if _NAME_PATTERN is None:
|
|
# Lazy import to speedup Python startup time
|
|
import re
|
|
dotted_words = r'(?!\d)(\w+)(\.(?!\d)(\w+))*'
|
|
_NAME_PATTERN = re.compile(f'^(?P<pkg>{dotted_words})'
|
|
f'(?P<cln>:(?P<obj>{dotted_words})?)?$',
|
|
re.UNICODE)
|
|
|
|
m = _NAME_PATTERN.match(name)
|
|
if not m:
|
|
raise ValueError(f'invalid format: {name!r}')
|
|
gd = m.groupdict()
|
|
if gd.get('cln'):
|
|
# there is a colon - a one-step import is all that's needed
|
|
mod = importlib.import_module(gd['pkg'])
|
|
parts = gd.get('obj')
|
|
parts = parts.split('.') if parts else []
|
|
else:
|
|
# no colon - have to iterate to find the package boundary
|
|
parts = name.split('.')
|
|
modname = parts.pop(0)
|
|
# first part *must* be a module/package.
|
|
mod = importlib.import_module(modname)
|
|
while parts:
|
|
p = parts[0]
|
|
s = f'{modname}.{p}'
|
|
try:
|
|
mod = importlib.import_module(s)
|
|
parts.pop(0)
|
|
modname = s
|
|
except ImportError:
|
|
break
|
|
# if we reach this point, mod is the module, already imported, and
|
|
# parts is the list of parts in the object hierarchy to be traversed, or
|
|
# an empty list if just the module is wanted.
|
|
result = mod
|
|
for p in parts:
|
|
result = getattr(result, p)
|
|
return result
|