Current File : //lib/python3.12/importlib/metadata/__init__.py
import os
import re
import abc
import csv
import sys
import email
import pathlib
import zipfile
import operator
import textwrap
import warnings
import functools
import itertools
import posixpath
import contextlib
import collections
import inspect
from . import _adapters, _meta
from ._collections import FreezableDefaultDict, Pair
from ._functools import method_cache, pass_none
from ._itertools import always_iterable, unique_everseen
from ._meta import PackageMetadata, SimplePath
from contextlib import suppress
from importlib import import_module
from importlib.abc import MetaPathFinder
from itertools import starmap
from typing import List, Mapping, Optional, cast
__all__ = [
'Distribution',
'DistributionFinder',
'PackageMetadata',
'PackageNotFoundError',
'distribution',
'distributions',
'entry_points',
'files',
'metadata',
'packages_distributions',
'requires',
'version',
]
class PackageNotFoundError(ModuleNotFoundError):
"""The package was not found."""
def __str__(self):
return f"No package metadata was found for {self.name}"
@property
def name(self):
(name,) = self.args
return name
class Sectioned:
"""
A simple entry point config parser for performance
>>> for item in Sectioned.read(Sectioned._sample):
... print(item)
Pair(name='sec1', value='# comments ignored')
Pair(name='sec1', value='a = 1')
Pair(name='sec1', value='b = 2')
Pair(name='sec2', value='a = 2')
>>> res = Sectioned.section_pairs(Sectioned._sample)
>>> item = next(res)
>>> item.name
'sec1'
>>> item.value
Pair(name='a', value='1')
>>> item = next(res)
>>> item.value
Pair(name='b', value='2')
>>> item = next(res)
>>> item.name
'sec2'
>>> item.value
Pair(name='a', value='2')
>>> list(res)
[]
"""
_sample = textwrap.dedent(
"""
[sec1]
# comments ignored
a = 1
b = 2
[sec2]
a = 2
"""
).lstrip()
@classmethod
def section_pairs(cls, text):
return (
section._replace(value=Pair.parse(section.value))
for section in cls.read(text, filter_=cls.valid)
if section.name is not None
)
@staticmethod
def read(text, filter_=None):
lines = filter(filter_, map(str.strip, text.splitlines()))
name = None
for value in lines:
section_match = value.startswith('[') and value.endswith(']')
if section_match:
name = value.strip('[]')
continue
yield Pair(name, value)
@staticmethod
def valid(line):
return line and not line.startswith('#')
class DeprecatedTuple:
"""
Provide subscript item access for backward compatibility.
>>> recwarn = getfixture('recwarn')
>>> ep = EntryPoint(name='name', value='value', group='group')
>>> ep[:]
('name', 'value', 'group')
>>> ep[0]
'name'
>>> len(recwarn)
1
"""
# Do not remove prior to 2023-05-01 or Python 3.13
_warn = functools.partial(
warnings.warn,
"EntryPoint tuple interface is deprecated. Access members by name.",
DeprecationWarning,
stacklevel=2,
)
def __getitem__(self, item):
self._warn()
return self._key()[item]
class EntryPoint(DeprecatedTuple):
"""An entry point as defined by Python packaging conventions.
See `the packaging docs on entry points
<https://packaging.python.org/specifications/entry-points/>`_
for more information.
>>> ep = EntryPoint(
... name=None, group=None, value='package.module:attr [extra1, extra2]')
>>> ep.module
'package.module'
>>> ep.attr
'attr'
>>> ep.extras
['extra1', 'extra2']
"""
pattern = re.compile(
r'(?P<module>[\w.]+)\s*'
r'(:\s*(?P<attr>[\w.]+)\s*)?'
r'((?P<extras>\[.*\])\s*)?$'
)
"""
A regular expression describing the syntax for an entry point,
which might look like:
- module
- package.module
- package.module:attribute
- package.module:object.attribute
- package.module:attr [extra1, extra2]
Other combinations are possible as well.
The expression is lenient about whitespace around the ':',
following the attr, and following any extras.
"""
name: str
value: str
group: str
dist: Optional['Distribution'] = None
def __init__(self, name, value, group):
vars(self).update(name=name, value=value, group=group)
def load(self):
"""Load the entry point from its definition. If only a module
is indicated by the value, return that module. Otherwise,
return the named object.
"""
match = self.pattern.match(self.value)
module = import_module(match.group('module'))
attrs = filter(None, (match.group('attr') or '').split('.'))
return functools.reduce(getattr, attrs, module)
@property
def module(self):
match = self.pattern.match(self.value)
return match.group('module')
@property
def attr(self):
match = self.pattern.match(self.value)
return match.group('attr')
@property
def extras(self):
match = self.pattern.match(self.value)
return re.findall(r'\w+', match.group('extras') or '')
def _for(self, dist):
vars(self).update(dist=dist)
return self
def matches(self, **params):
"""
EntryPoint matches the given parameters.
>>> ep = EntryPoint(group='foo', name='bar', value='bing:bong [extra1, extra2]')
>>> ep.matches(group='foo')
True
>>> ep.matches(name='bar', value='bing:bong [extra1, extra2]')
True
>>> ep.matches(group='foo', name='other')
False
>>> ep.matches()
True
>>> ep.matches(extras=['extra1', 'extra2'])
True
>>> ep.matches(module='bing')
True
>>> ep.matches(attr='bong')
True
"""
attrs = (getattr(self, param) for param in params)
return all(map(operator.eq, params.values(), attrs))
def _key(self):
return self.name, self.value, self.group
def __lt__(self, other):
return self._key() < other._key()
def __eq__(self, other):
return self._key() == other._key()
def __setattr__(self, name, value):
raise AttributeError("EntryPoint objects are immutable.")
def __repr__(self):
return (
f'EntryPoint(name={self.name!r}, value={self.value!r}, '
f'group={self.group!r})'
)
def __hash__(self):
return hash(self._key())
class EntryPoints(tuple):
"""
An immutable collection of selectable EntryPoint objects.
"""
__slots__ = ()
def __getitem__(self, name): # -> EntryPoint:
"""
Get the EntryPoint in self matching name.
"""
try:
return next(iter(self.select(name=name)))
except StopIteration:
raise KeyError(name)
def select(self, **params):
"""
Select entry points from self that match the
given parameters (typically group and/or name).
"""
return EntryPoints(ep for ep in self if ep.matches(**params))
@property
def names(self):
"""
Return the set of all names of all entry points.
"""
return {ep.name for ep in self}
@property
def groups(self):
"""
Return the set of all groups of all entry points.
"""
return {ep.group for ep in self}
@classmethod
def _from_text_for(cls, text, dist):
return cls(ep._for(dist) for ep in cls._from_text(text))
@staticmethod
def _from_text(text):
return (
EntryPoint(name=item.value.name, value=item.value.value, group=item.name)
for item in Sectioned.section_pairs(text or '')
)
class PackagePath(pathlib.PurePosixPath):
"""A reference to a path in a package"""
def read_text(self, encoding='utf-8'):
with self.locate().open(encoding=encoding) as stream:
return stream.read()
def read_binary(self):
with self.locate().open('rb') as stream:
return stream.read()
def locate(self):
"""Return a path-like object for this path"""
return self.dist.locate_file(self)
class FileHash:
def __init__(self, spec):
self.mode, _, self.value = spec.partition('=')
def __repr__(self):
return f'<FileHash mode: {self.mode} value: {self.value}>'
class DeprecatedNonAbstract:
def __new__(cls, *args, **kwargs):
all_names = {
name for subclass in inspect.getmro(cls) for name in vars(subclass)
}
abstract = {
name
for name in all_names
if getattr(getattr(cls, name), '__isabstractmethod__', False)
}
if abstract:
warnings.warn(
f"Unimplemented abstract methods {abstract}",
DeprecationWarning,
stacklevel=2,
)
return super().__new__(cls)
class Distribution(DeprecatedNonAbstract):
"""A Python distribution package."""
@abc.abstractmethod
def read_text(self, filename) -> Optional[str]:
"""Attempt to load metadata file given by the name.
:param filename: The name of the file in the distribution info.
:return: The text if found, otherwise None.
"""
@abc.abstractmethod
def locate_file(self, path):
"""
Given a path to a file in this distribution, return a path
to it.
"""
@classmethod
def from_name(cls, name: str):
"""Return the Distribution for the given package name.
:param name: The name of the distribution package to search for.
:return: The Distribution instance (or subclass thereof) for the named
package, if found.
:raises PackageNotFoundError: When the named package's distribution
metadata cannot be found.
:raises ValueError: When an invalid value is supplied for name.
"""
if not name:
raise ValueError("A distribution name is required.")
try:
return next(cls.discover(name=name))
except StopIteration:
raise PackageNotFoundError(name)
@classmethod
def discover(cls, **kwargs):
"""Return an iterable of Distribution objects for all packages.
Pass a ``context`` or pass keyword arguments for constructing
a context.
:context: A ``DistributionFinder.Context`` object.
:return: Iterable of Distribution objects for all packages.
"""
context = kwargs.pop('context', None)
if context and kwargs:
raise ValueError("cannot accept context and kwargs")
context = context or DistributionFinder.Context(**kwargs)
return itertools.chain.from_iterable(
resolver(context) for resolver in cls._discover_resolvers()
)
@staticmethod
def at(path):
"""Return a Distribution for the indicated metadata path
:param path: a string or path-like object
:return: a concrete Distribution instance for the path
"""
return PathDistribution(pathlib.Path(path))
@staticmethod
def _discover_resolvers():
"""Search the meta_path for resolvers."""
declared = (
getattr(finder, 'find_distributions', None) for finder in sys.meta_path
)
return filter(None, declared)
@property
def metadata(self) -> _meta.PackageMetadata:
"""Return the parsed metadata for this Distribution.
The returned object will have keys that name the various bits of
metadata. See PEP 566 for details.
"""
opt_text = (
self.read_text('METADATA')
or self.read_text('PKG-INFO')
# This last clause is here to support old egg-info files. Its
# effect is to just end up using the PathDistribution's self._path
# (which points to the egg-info file) attribute unchanged.
or self.read_text('')
)
text = cast(str, opt_text)
return _adapters.Message(email.message_from_string(text))
@property
def name(self):
"""Return the 'Name' metadata for the distribution package."""
return self.metadata['Name']
@property
def _normalized_name(self):
"""Return a normalized version of the name."""
return Prepared.normalize(self.name)
@property
def version(self):
"""Return the 'Version' metadata for the distribution package."""
return self.metadata['Version']
@property
def entry_points(self):
return EntryPoints._from_text_for(self.read_text('entry_points.txt'), self)
@property
def files(self):
"""Files in this distribution.
:return: List of PackagePath for this distribution or None
Result is `None` if the metadata file that enumerates files
(i.e. RECORD for dist-info, or installed-files.txt or
SOURCES.txt for egg-info) is missing.
Result may be empty if the metadata exists but is empty.
"""
def make_file(name, hash=None, size_str=None):
result = PackagePath(name)
result.hash = FileHash(hash) if hash else None
result.size = int(size_str) if size_str else None
result.dist = self
return result
@pass_none
def make_files(lines):
return starmap(make_file, csv.reader(lines))
@pass_none
def skip_missing_files(package_paths):
return list(filter(lambda path: path.locate().exists(), package_paths))
return skip_missing_files(
make_files(
self._read_files_distinfo()
or self._read_files_egginfo_installed()
or self._read_files_egginfo_sources()
)
)
def _read_files_distinfo(self):
"""
Read the lines of RECORD
"""
text = self.read_text('RECORD')
return text and text.splitlines()
def _read_files_egginfo_installed(self):
"""
Read installed-files.txt and return lines in a similar
CSV-parsable format as RECORD: each file must be placed
relative to the site-packages directory and must also be
quoted (since file names can contain literal commas).
This file is written when the package is installed by pip,
but it might not be written for other installation methods.
Assume the file is accurate if it exists.
"""
text = self.read_text('installed-files.txt')
# Prepend the .egg-info/ subdir to the lines in this file.
# But this subdir is only available from PathDistribution's
# self._path.
subdir = getattr(self, '_path', None)
if not text or not subdir:
return
paths = (
(subdir / name)
.resolve()
.relative_to(self.locate_file('').resolve())
.as_posix()
for name in text.splitlines()
)
return map('"{}"'.format, paths)
def _read_files_egginfo_sources(self):
"""
Read SOURCES.txt and return lines in a similar CSV-parsable
format as RECORD: each file name must be quoted (since it
might contain literal commas).
Note that SOURCES.txt is not a reliable source for what
files are installed by a package. This file is generated
for a source archive, and the files that are present
there (e.g. setup.py) may not correctly reflect the files
that are present after the package has been installed.
"""
text = self.read_text('SOURCES.txt')
return text and map('"{}"'.format, text.splitlines())
@property
def requires(self):
"""Generated requirements specified for this Distribution"""
reqs = self._read_dist_info_reqs() or self._read_egg_info_reqs()
return reqs and list(reqs)
def _read_dist_info_reqs(self):
return self.metadata.get_all('Requires-Dist')
def _read_egg_info_reqs(self):
source = self.read_text('requires.txt')
return pass_none(self._deps_from_requires_text)(source)
@classmethod
def _deps_from_requires_text(cls, source):
return cls._convert_egg_info_reqs_to_simple_reqs(Sectioned.read(source))
@staticmethod
def _convert_egg_info_reqs_to_simple_reqs(sections):
"""
Historically, setuptools would solicit and store 'extra'
requirements, including those with environment markers,
in separate sections. More modern tools expect each
dependency to be defined separately, with any relevant
extras and environment markers attached directly to that
requirement. This method converts the former to the
latter. See _test_deps_from_requires_text for an example.
"""
def make_condition(name):
return name and f'extra == "{name}"'
def quoted_marker(section):
section = section or ''
extra, sep, markers = section.partition(':')
if extra and markers:
markers = f'({markers})'
conditions = list(filter(None, [markers, make_condition(extra)]))
return '; ' + ' and '.join(conditions) if conditions else ''
def url_req_space(req):
"""
PEP 508 requires a space between the url_spec and the quoted_marker.
Ref python/importlib_metadata#357.
"""
# '@' is uniquely indicative of a url_req.
return ' ' * ('@' in req)
for section in sections:
space = url_req_space(section.value)
yield section.value + space + quoted_marker(section.name)
class DistributionFinder(MetaPathFinder):
"""
A MetaPathFinder capable of discovering installed distributions.
"""
class Context:
"""
Keyword arguments presented by the caller to
``distributions()`` or ``Distribution.discover()``
to narrow the scope of a search for distributions
in all DistributionFinders.
Each DistributionFinder may expect any parameters
and should attempt to honor the canonical
parameters defined below when appropriate.
"""
name = None
"""
Specific name for which a distribution finder should match.
A name of ``None`` matches all distributions.
"""
def __init__(self, **kwargs):
vars(self).update(kwargs)
@property
def path(self):
"""
The sequence of directory path that a distribution finder
should search.
Typically refers to Python installed package paths such as
"site-packages" directories and defaults to ``sys.path``.
"""
return vars(self).get('path', sys.path)
@abc.abstractmethod
def find_distributions(self, context=Context()):
"""
Find distributions.
Return an iterable of all Distribution instances capable of
loading the metadata for packages matching the ``context``,
a DistributionFinder.Context instance.
"""
class FastPath:
"""
Micro-optimized class for searching a path for
children.
>>> FastPath('').children()
['...']
"""
@functools.lru_cache() # type: ignore
def __new__(cls, root):
return super().__new__(cls)
def __init__(self, root):
self.root = root
def joinpath(self, child):
return pathlib.Path(self.root, child)
def children(self):
with suppress(Exception):
return os.listdir(self.root or '.')
with suppress(Exception):
return self.zip_children()
return []
def zip_children(self):
zip_path = zipfile.Path(self.root)
names = zip_path.root.namelist()
self.joinpath = zip_path.joinpath
return dict.fromkeys(child.split(posixpath.sep, 1)[0] for child in names)
def search(self, name):
return self.lookup(self.mtime).search(name)
@property
def mtime(self):
with suppress(OSError):
return os.stat(self.root).st_mtime
self.lookup.cache_clear()
@method_cache
def lookup(self, mtime):
return Lookup(self)
class Lookup:
def __init__(self, path: FastPath):
base = os.path.basename(path.root).lower()
base_is_egg = base.endswith(".egg")
self.infos = FreezableDefaultDict(list)
self.eggs = FreezableDefaultDict(list)
for child in path.children():
low = child.lower()
if low.endswith((".dist-info", ".egg-info")):
# rpartition is faster than splitext and suitable for this purpose.
name = low.rpartition(".")[0].partition("-")[0]
normalized = Prepared.normalize(name)
self.infos[normalized].append(path.joinpath(child))
elif base_is_egg and low == "egg-info":
name = base.rpartition(".")[0].partition("-")[0]
legacy_normalized = Prepared.legacy_normalize(name)
self.eggs[legacy_normalized].append(path.joinpath(child))
self.infos.freeze()
self.eggs.freeze()
def search(self, prepared):
infos = (
self.infos[prepared.normalized]
if prepared
else itertools.chain.from_iterable(self.infos.values())
)
eggs = (
self.eggs[prepared.legacy_normalized]
if prepared
else itertools.chain.from_iterable(self.eggs.values())
)
return itertools.chain(infos, eggs)
class Prepared:
"""
A prepared search for metadata on a possibly-named package.
"""
normalized = None
legacy_normalized = None
def __init__(self, name):
self.name = name
if name is None:
return
self.normalized = self.normalize(name)
self.legacy_normalized = self.legacy_normalize(name)
@staticmethod
def normalize(name):
"""
PEP 503 normalization plus dashes as underscores.
"""
return re.sub(r"[-_.]+", "-", name).lower().replace('-', '_')
@staticmethod
def legacy_normalize(name):
"""
Normalize the package name as found in the convention in
older packaging tools versions and specs.
"""
return name.lower().replace('-', '_')
def __bool__(self):
return bool(self.name)
class MetadataPathFinder(DistributionFinder):
@classmethod
def find_distributions(cls, context=DistributionFinder.Context()):
"""
Find distributions.
Return an iterable of all Distribution instances capable of
loading the metadata for packages matching ``context.name``
(or all names if ``None`` indicated) along the paths in the list
of directories ``context.path``.
"""
found = cls._search_paths(context.name, context.path)
return map(PathDistribution, found)
@classmethod
def _search_paths(cls, name, paths):
"""Find metadata directories in paths heuristically."""
prepared = Prepared(name)
return itertools.chain.from_iterable(
path.search(prepared) for path in map(FastPath, paths)
)
@classmethod
def invalidate_caches(cls):
FastPath.__new__.cache_clear()
class PathDistribution(Distribution):
def __init__(self, path: SimplePath):
"""Construct a distribution.
:param path: SimplePath indicating the metadata directory.
"""
self._path = path
def read_text(self, filename):
with suppress(
FileNotFoundError,
IsADirectoryError,
KeyError,
NotADirectoryError,
PermissionError,
):
return self._path.joinpath(filename).read_text(encoding='utf-8')
read_text.__doc__ = Distribution.read_text.__doc__
def locate_file(self, path):
return self._path.parent / path
@property
def _normalized_name(self):
"""
Performance optimization: where possible, resolve the
normalized name from the file system path.
"""
stem = os.path.basename(str(self._path))
return (
pass_none(Prepared.normalize)(self._name_from_stem(stem))
or super()._normalized_name
)
@staticmethod
def _name_from_stem(stem):
"""
>>> PathDistribution._name_from_stem('foo-3.0.egg-info')
'foo'
>>> PathDistribution._name_from_stem('CherryPy-3.0.dist-info')
'CherryPy'
>>> PathDistribution._name_from_stem('face.egg-info')
'face'
>>> PathDistribution._name_from_stem('foo.bar')
"""
filename, ext = os.path.splitext(stem)
if ext not in ('.dist-info', '.egg-info'):
return
name, sep, rest = filename.partition('-')
return name
def distribution(distribution_name):
"""Get the ``Distribution`` instance for the named package.
:param distribution_name: The name of the distribution package as a string.
:return: A ``Distribution`` instance (or subclass thereof).
"""
return Distribution.from_name(distribution_name)
def distributions(**kwargs):
"""Get all ``Distribution`` instances in the current environment.
:return: An iterable of ``Distribution`` instances.
"""
return Distribution.discover(**kwargs)
def metadata(distribution_name) -> _meta.PackageMetadata:
"""Get the metadata for the named package.
:param distribution_name: The name of the distribution package to query.
:return: A PackageMetadata containing the parsed metadata.
"""
return Distribution.from_name(distribution_name).metadata
def version(distribution_name):
"""Get the version string for the named package.
:param distribution_name: The name of the distribution package to query.
:return: The version string for the package as defined in the package's
"Version" metadata key.
"""
return distribution(distribution_name).version
_unique = functools.partial(
unique_everseen,
key=operator.attrgetter('_normalized_name'),
)
"""
Wrapper for ``distributions`` to return unique distributions by name.
"""
def entry_points(**params) -> EntryPoints:
"""Return EntryPoint objects for all installed packages.
Pass selection parameters (group or name) to filter the
result to entry points matching those properties (see
EntryPoints.select()).
:return: EntryPoints for all installed packages.
"""
eps = itertools.chain.from_iterable(
dist.entry_points for dist in _unique(distributions())
)
return EntryPoints(eps).select(**params)
def files(distribution_name):
"""Return a list of files for the named package.
:param distribution_name: The name of the distribution package to query.
:return: List of files composing the distribution.
"""
return distribution(distribution_name).files
def requires(distribution_name):
"""
Return a list of requirements for the named package.
:return: An iterator of requirements, suitable for
packaging.requirement.Requirement.
"""
return distribution(distribution_name).requires
def packages_distributions() -> Mapping[str, List[str]]:
"""
Return a mapping of top-level packages to their
distributions.
>>> import collections.abc
>>> pkgs = packages_distributions()
>>> all(isinstance(dist, collections.abc.Sequence) for dist in pkgs.values())
True
"""
pkg_to_dist = collections.defaultdict(list)
for dist in distributions():
for pkg in _top_level_declared(dist) or _top_level_inferred(dist):
pkg_to_dist[pkg].append(dist.metadata['Name'])
return dict(pkg_to_dist)
def _top_level_declared(dist):
return (dist.read_text('top_level.txt') or '').split()
def _top_level_inferred(dist):
opt_names = {
f.parts[0] if len(f.parts) > 1 else inspect.getmodulename(f)
for f in always_iterable(dist.files)
}
@pass_none
def importable_name(name):
return '.' not in name
return filter(importable_name, opt_names)
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