876 lines
32 KiB
Python
876 lines
32 KiB
Python
import importlib.util
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import os
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import pkgutil
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import sys
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import typing as t
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from collections import defaultdict
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from functools import update_wrapper
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from json import JSONDecoder
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from json import JSONEncoder
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from jinja2 import FileSystemLoader
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from werkzeug.exceptions import default_exceptions
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from werkzeug.exceptions import HTTPException
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from .cli import AppGroup
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from .globals import current_app
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from .helpers import get_root_path
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from .helpers import locked_cached_property
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from .helpers import send_from_directory
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from .templating import _default_template_ctx_processor
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from .typing import AfterRequestCallable
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from .typing import AppOrBlueprintKey
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from .typing import BeforeRequestCallable
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from .typing import GenericException
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from .typing import TeardownCallable
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from .typing import TemplateContextProcessorCallable
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from .typing import URLDefaultCallable
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from .typing import URLValuePreprocessorCallable
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if t.TYPE_CHECKING:
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from .wrappers import Response
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from .typing import ErrorHandlerCallable
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# a singleton sentinel value for parameter defaults
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_sentinel = object()
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F = t.TypeVar("F", bound=t.Callable[..., t.Any])
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def setupmethod(f: F) -> F:
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"""Wraps a method so that it performs a check in debug mode if the
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first request was already handled.
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"""
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def wrapper_func(self, *args: t.Any, **kwargs: t.Any) -> t.Any:
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if self._is_setup_finished():
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raise AssertionError(
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"A setup function was called after the first request "
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"was handled. This usually indicates a bug in the"
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" application where a module was not imported and"
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" decorators or other functionality was called too"
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" late.\nTo fix this make sure to import all your view"
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" modules, database models, and everything related at a"
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" central place before the application starts serving"
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" requests."
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)
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return f(self, *args, **kwargs)
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return t.cast(F, update_wrapper(wrapper_func, f))
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class Scaffold:
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"""Common behavior shared between :class:`~flask.Flask` and
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:class:`~flask.blueprints.Blueprint`.
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:param import_name: The import name of the module where this object
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is defined. Usually :attr:`__name__` should be used.
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:param static_folder: Path to a folder of static files to serve.
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If this is set, a static route will be added.
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:param static_url_path: URL prefix for the static route.
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:param template_folder: Path to a folder containing template files.
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for rendering. If this is set, a Jinja loader will be added.
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:param root_path: The path that static, template, and resource files
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are relative to. Typically not set, it is discovered based on
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the ``import_name``.
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.. versionadded:: 2.0
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"""
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name: str
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_static_folder: t.Optional[str] = None
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_static_url_path: t.Optional[str] = None
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#: JSON encoder class used by :func:`flask.json.dumps`. If a
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#: blueprint sets this, it will be used instead of the app's value.
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json_encoder: t.Optional[t.Type[JSONEncoder]] = None
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#: JSON decoder class used by :func:`flask.json.loads`. If a
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#: blueprint sets this, it will be used instead of the app's value.
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json_decoder: t.Optional[t.Type[JSONDecoder]] = None
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def __init__(
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self,
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import_name: str,
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static_folder: t.Optional[t.Union[str, os.PathLike]] = None,
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static_url_path: t.Optional[str] = None,
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template_folder: t.Optional[str] = None,
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root_path: t.Optional[str] = None,
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):
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#: The name of the package or module that this object belongs
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#: to. Do not change this once it is set by the constructor.
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self.import_name = import_name
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self.static_folder = static_folder # type: ignore
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self.static_url_path = static_url_path
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#: The path to the templates folder, relative to
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#: :attr:`root_path`, to add to the template loader. ``None`` if
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#: templates should not be added.
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self.template_folder = template_folder
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if root_path is None:
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root_path = get_root_path(self.import_name)
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#: Absolute path to the package on the filesystem. Used to look
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#: up resources contained in the package.
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self.root_path = root_path
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#: The Click command group for registering CLI commands for this
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#: object. The commands are available from the ``flask`` command
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#: once the application has been discovered and blueprints have
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#: been registered.
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self.cli = AppGroup()
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#: A dictionary mapping endpoint names to view functions.
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#:
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#: To register a view function, use the :meth:`route` decorator.
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#:
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#: This data structure is internal. It should not be modified
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#: directly and its format may change at any time.
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self.view_functions: t.Dict[str, t.Callable] = {}
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#: A data structure of registered error handlers, in the format
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#: ``{scope: {code: {class: handler}}}```. The ``scope`` key is
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#: the name of a blueprint the handlers are active for, or
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#: ``None`` for all requests. The ``code`` key is the HTTP
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#: status code for ``HTTPException``, or ``None`` for
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#: other exceptions. The innermost dictionary maps exception
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#: classes to handler functions.
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#:
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#: To register an error handler, use the :meth:`errorhandler`
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#: decorator.
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#:
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#: This data structure is internal. It should not be modified
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#: directly and its format may change at any time.
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self.error_handler_spec: t.Dict[
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AppOrBlueprintKey,
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t.Dict[
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t.Optional[int],
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t.Dict[t.Type[Exception], "ErrorHandlerCallable[Exception]"],
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],
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] = defaultdict(lambda: defaultdict(dict))
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#: A data structure of functions to call at the beginning of
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#: each request, in the format ``{scope: [functions]}``. The
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#: ``scope`` key is the name of a blueprint the functions are
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#: active for, or ``None`` for all requests.
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#:
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#: To register a function, use the :meth:`before_request`
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#: decorator.
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#:
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#: This data structure is internal. It should not be modified
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#: directly and its format may change at any time.
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self.before_request_funcs: t.Dict[
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AppOrBlueprintKey, t.List[BeforeRequestCallable]
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] = defaultdict(list)
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#: A data structure of functions to call at the end of each
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#: request, in the format ``{scope: [functions]}``. The
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#: ``scope`` key is the name of a blueprint the functions are
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#: active for, or ``None`` for all requests.
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#:
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#: To register a function, use the :meth:`after_request`
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#: decorator.
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#:
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#: This data structure is internal. It should not be modified
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#: directly and its format may change at any time.
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self.after_request_funcs: t.Dict[
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AppOrBlueprintKey, t.List[AfterRequestCallable]
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] = defaultdict(list)
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#: A data structure of functions to call at the end of each
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#: request even if an exception is raised, in the format
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#: ``{scope: [functions]}``. The ``scope`` key is the name of a
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#: blueprint the functions are active for, or ``None`` for all
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#: requests.
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#:
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#: To register a function, use the :meth:`teardown_request`
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#: decorator.
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#:
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#: This data structure is internal. It should not be modified
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#: directly and its format may change at any time.
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self.teardown_request_funcs: t.Dict[
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AppOrBlueprintKey, t.List[TeardownCallable]
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] = defaultdict(list)
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#: A data structure of functions to call to pass extra context
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#: values when rendering templates, in the format
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#: ``{scope: [functions]}``. The ``scope`` key is the name of a
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#: blueprint the functions are active for, or ``None`` for all
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#: requests.
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#:
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#: To register a function, use the :meth:`context_processor`
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#: decorator.
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#:
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#: This data structure is internal. It should not be modified
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#: directly and its format may change at any time.
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self.template_context_processors: t.Dict[
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AppOrBlueprintKey, t.List[TemplateContextProcessorCallable]
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] = defaultdict(list, {None: [_default_template_ctx_processor]})
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#: A data structure of functions to call to modify the keyword
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#: arguments passed to the view function, in the format
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#: ``{scope: [functions]}``. The ``scope`` key is the name of a
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#: blueprint the functions are active for, or ``None`` for all
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#: requests.
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#:
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#: To register a function, use the
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#: :meth:`url_value_preprocessor` decorator.
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#:
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#: This data structure is internal. It should not be modified
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#: directly and its format may change at any time.
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self.url_value_preprocessors: t.Dict[
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AppOrBlueprintKey,
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t.List[URLValuePreprocessorCallable],
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] = defaultdict(list)
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#: A data structure of functions to call to modify the keyword
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#: arguments when generating URLs, in the format
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#: ``{scope: [functions]}``. The ``scope`` key is the name of a
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#: blueprint the functions are active for, or ``None`` for all
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#: requests.
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#:
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#: To register a function, use the :meth:`url_defaults`
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#: decorator.
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#:
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#: This data structure is internal. It should not be modified
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#: directly and its format may change at any time.
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self.url_default_functions: t.Dict[
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AppOrBlueprintKey, t.List[URLDefaultCallable]
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] = defaultdict(list)
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def __repr__(self) -> str:
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return f"<{type(self).__name__} {self.name!r}>"
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def _is_setup_finished(self) -> bool:
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raise NotImplementedError
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@property
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def static_folder(self) -> t.Optional[str]:
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"""The absolute path to the configured static folder. ``None``
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if no static folder is set.
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"""
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if self._static_folder is not None:
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return os.path.join(self.root_path, self._static_folder)
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else:
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return None
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@static_folder.setter
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def static_folder(self, value: t.Optional[t.Union[str, os.PathLike]]) -> None:
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if value is not None:
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value = os.fspath(value).rstrip(r"\/")
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self._static_folder = value
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@property
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def has_static_folder(self) -> bool:
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"""``True`` if :attr:`static_folder` is set.
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.. versionadded:: 0.5
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"""
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return self.static_folder is not None
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@property
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def static_url_path(self) -> t.Optional[str]:
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"""The URL prefix that the static route will be accessible from.
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If it was not configured during init, it is derived from
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:attr:`static_folder`.
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"""
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if self._static_url_path is not None:
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return self._static_url_path
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if self.static_folder is not None:
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basename = os.path.basename(self.static_folder)
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return f"/{basename}".rstrip("/")
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return None
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@static_url_path.setter
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def static_url_path(self, value: t.Optional[str]) -> None:
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if value is not None:
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value = value.rstrip("/")
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self._static_url_path = value
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def get_send_file_max_age(self, filename: t.Optional[str]) -> t.Optional[int]:
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"""Used by :func:`send_file` to determine the ``max_age`` cache
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value for a given file path if it wasn't passed.
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By default, this returns :data:`SEND_FILE_MAX_AGE_DEFAULT` from
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the configuration of :data:`~flask.current_app`. This defaults
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to ``None``, which tells the browser to use conditional requests
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instead of a timed cache, which is usually preferable.
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.. versionchanged:: 2.0
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The default configuration is ``None`` instead of 12 hours.
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.. versionadded:: 0.9
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"""
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value = current_app.send_file_max_age_default
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if value is None:
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return None
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return int(value.total_seconds())
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def send_static_file(self, filename: str) -> "Response":
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"""The view function used to serve files from
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:attr:`static_folder`. A route is automatically registered for
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this view at :attr:`static_url_path` if :attr:`static_folder` is
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set.
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.. versionadded:: 0.5
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"""
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if not self.has_static_folder:
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raise RuntimeError("'static_folder' must be set to serve static_files.")
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# send_file only knows to call get_send_file_max_age on the app,
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# call it here so it works for blueprints too.
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max_age = self.get_send_file_max_age(filename)
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return send_from_directory(
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t.cast(str, self.static_folder), filename, max_age=max_age
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)
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@locked_cached_property
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def jinja_loader(self) -> t.Optional[FileSystemLoader]:
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"""The Jinja loader for this object's templates. By default this
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is a class :class:`jinja2.loaders.FileSystemLoader` to
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:attr:`template_folder` if it is set.
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.. versionadded:: 0.5
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"""
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if self.template_folder is not None:
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return FileSystemLoader(os.path.join(self.root_path, self.template_folder))
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else:
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return None
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def open_resource(self, resource: str, mode: str = "rb") -> t.IO[t.AnyStr]:
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"""Open a resource file relative to :attr:`root_path` for
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reading.
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For example, if the file ``schema.sql`` is next to the file
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``app.py`` where the ``Flask`` app is defined, it can be opened
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with:
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.. code-block:: python
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with app.open_resource("schema.sql") as f:
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conn.executescript(f.read())
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:param resource: Path to the resource relative to
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:attr:`root_path`.
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:param mode: Open the file in this mode. Only reading is
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supported, valid values are "r" (or "rt") and "rb".
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"""
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if mode not in {"r", "rt", "rb"}:
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raise ValueError("Resources can only be opened for reading.")
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return open(os.path.join(self.root_path, resource), mode)
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def _method_route(self, method: str, rule: str, options: dict) -> t.Callable:
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if "methods" in options:
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raise TypeError("Use the 'route' decorator to use the 'methods' argument.")
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return self.route(rule, methods=[method], **options)
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def get(self, rule: str, **options: t.Any) -> t.Callable:
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"""Shortcut for :meth:`route` with ``methods=["GET"]``.
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.. versionadded:: 2.0
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"""
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return self._method_route("GET", rule, options)
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def post(self, rule: str, **options: t.Any) -> t.Callable:
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"""Shortcut for :meth:`route` with ``methods=["POST"]``.
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.. versionadded:: 2.0
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"""
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return self._method_route("POST", rule, options)
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def put(self, rule: str, **options: t.Any) -> t.Callable:
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"""Shortcut for :meth:`route` with ``methods=["PUT"]``.
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.. versionadded:: 2.0
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"""
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return self._method_route("PUT", rule, options)
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def delete(self, rule: str, **options: t.Any) -> t.Callable:
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"""Shortcut for :meth:`route` with ``methods=["DELETE"]``.
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.. versionadded:: 2.0
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"""
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return self._method_route("DELETE", rule, options)
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def patch(self, rule: str, **options: t.Any) -> t.Callable:
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"""Shortcut for :meth:`route` with ``methods=["PATCH"]``.
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.. versionadded:: 2.0
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"""
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return self._method_route("PATCH", rule, options)
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def route(self, rule: str, **options: t.Any) -> t.Callable:
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"""Decorate a view function to register it with the given URL
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rule and options. Calls :meth:`add_url_rule`, which has more
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details about the implementation.
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.. code-block:: python
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@app.route("/")
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def index():
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return "Hello, World!"
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See :ref:`url-route-registrations`.
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The endpoint name for the route defaults to the name of the view
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function if the ``endpoint`` parameter isn't passed.
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The ``methods`` parameter defaults to ``["GET"]``. ``HEAD`` and
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``OPTIONS`` are added automatically.
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:param rule: The URL rule string.
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:param options: Extra options passed to the
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:class:`~werkzeug.routing.Rule` object.
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"""
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def decorator(f: t.Callable) -> t.Callable:
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endpoint = options.pop("endpoint", None)
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self.add_url_rule(rule, endpoint, f, **options)
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return f
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return decorator
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@setupmethod
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def add_url_rule(
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self,
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rule: str,
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endpoint: t.Optional[str] = None,
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view_func: t.Optional[t.Callable] = None,
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provide_automatic_options: t.Optional[bool] = None,
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**options: t.Any,
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) -> None:
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"""Register a rule for routing incoming requests and building
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URLs. The :meth:`route` decorator is a shortcut to call this
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with the ``view_func`` argument. These are equivalent:
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.. code-block:: python
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@app.route("/")
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def index():
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...
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.. code-block:: python
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def index():
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...
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app.add_url_rule("/", view_func=index)
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See :ref:`url-route-registrations`.
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The endpoint name for the route defaults to the name of the view
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function if the ``endpoint`` parameter isn't passed. An error
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will be raised if a function has already been registered for the
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endpoint.
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The ``methods`` parameter defaults to ``["GET"]``. ``HEAD`` is
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always added automatically, and ``OPTIONS`` is added
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automatically by default.
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``view_func`` does not necessarily need to be passed, but if the
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rule should participate in routing an endpoint name must be
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associated with a view function at some point with the
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:meth:`endpoint` decorator.
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.. code-block:: python
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app.add_url_rule("/", endpoint="index")
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@app.endpoint("index")
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def index():
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...
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If ``view_func`` has a ``required_methods`` attribute, those
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methods are added to the passed and automatic methods. If it
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has a ``provide_automatic_methods`` attribute, it is used as the
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default if the parameter is not passed.
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:param rule: The URL rule string.
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:param endpoint: The endpoint name to associate with the rule
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and view function. Used when routing and building URLs.
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Defaults to ``view_func.__name__``.
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:param view_func: The view function to associate with the
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endpoint name.
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:param provide_automatic_options: Add the ``OPTIONS`` method and
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respond to ``OPTIONS`` requests automatically.
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:param options: Extra options passed to the
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|
:class:`~werkzeug.routing.Rule` object.
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def endpoint(self, endpoint: str) -> t.Callable:
|
|
"""Decorate a view function to register it for the given
|
|
endpoint. Used if a rule is added without a ``view_func`` with
|
|
:meth:`add_url_rule`.
|
|
|
|
.. code-block:: python
|
|
|
|
app.add_url_rule("/ex", endpoint="example")
|
|
|
|
@app.endpoint("example")
|
|
def example():
|
|
...
|
|
|
|
:param endpoint: The endpoint name to associate with the view
|
|
function.
|
|
"""
|
|
|
|
def decorator(f):
|
|
self.view_functions[endpoint] = f
|
|
return f
|
|
|
|
return decorator
|
|
|
|
@setupmethod
|
|
def before_request(self, f: BeforeRequestCallable) -> BeforeRequestCallable:
|
|
"""Register a function to run before each request.
|
|
|
|
For example, this can be used to open a database connection, or
|
|
to load the logged in user from the session.
|
|
|
|
.. code-block:: python
|
|
|
|
@app.before_request
|
|
def load_user():
|
|
if "user_id" in session:
|
|
g.user = db.session.get(session["user_id"])
|
|
|
|
The function will be called without any arguments. If it returns
|
|
a non-``None`` value, the value is handled as if it was the
|
|
return value from the view, and further request handling is
|
|
stopped.
|
|
"""
|
|
self.before_request_funcs.setdefault(None, []).append(f)
|
|
return f
|
|
|
|
@setupmethod
|
|
def after_request(self, f: AfterRequestCallable) -> AfterRequestCallable:
|
|
"""Register a function to run after each request to this object.
|
|
|
|
The function is called with the response object, and must return
|
|
a response object. This allows the functions to modify or
|
|
replace the response before it is sent.
|
|
|
|
If a function raises an exception, any remaining
|
|
``after_request`` functions will not be called. Therefore, this
|
|
should not be used for actions that must execute, such as to
|
|
close resources. Use :meth:`teardown_request` for that.
|
|
"""
|
|
self.after_request_funcs.setdefault(None, []).append(f)
|
|
return f
|
|
|
|
@setupmethod
|
|
def teardown_request(self, f: TeardownCallable) -> TeardownCallable:
|
|
"""Register a function to be run at the end of each request,
|
|
regardless of whether there was an exception or not. These functions
|
|
are executed when the request context is popped, even if not an
|
|
actual request was performed.
|
|
|
|
Example::
|
|
|
|
ctx = app.test_request_context()
|
|
ctx.push()
|
|
...
|
|
ctx.pop()
|
|
|
|
When ``ctx.pop()`` is executed in the above example, the teardown
|
|
functions are called just before the request context moves from the
|
|
stack of active contexts. This becomes relevant if you are using
|
|
such constructs in tests.
|
|
|
|
Teardown functions must avoid raising exceptions, since they . If they
|
|
execute code that might fail they
|
|
will have to surround the execution of these code by try/except
|
|
statements and log occurring errors.
|
|
|
|
When a teardown function was called because of an exception it will
|
|
be passed an error object.
|
|
|
|
The return values of teardown functions are ignored.
|
|
|
|
.. admonition:: Debug Note
|
|
|
|
In debug mode Flask will not tear down a request on an exception
|
|
immediately. Instead it will keep it alive so that the interactive
|
|
debugger can still access it. This behavior can be controlled
|
|
by the ``PRESERVE_CONTEXT_ON_EXCEPTION`` configuration variable.
|
|
"""
|
|
self.teardown_request_funcs.setdefault(None, []).append(f)
|
|
return f
|
|
|
|
@setupmethod
|
|
def context_processor(
|
|
self, f: TemplateContextProcessorCallable
|
|
) -> TemplateContextProcessorCallable:
|
|
"""Registers a template context processor function."""
|
|
self.template_context_processors[None].append(f)
|
|
return f
|
|
|
|
@setupmethod
|
|
def url_value_preprocessor(
|
|
self, f: URLValuePreprocessorCallable
|
|
) -> URLValuePreprocessorCallable:
|
|
"""Register a URL value preprocessor function for all view
|
|
functions in the application. These functions will be called before the
|
|
:meth:`before_request` functions.
|
|
|
|
The function can modify the values captured from the matched url before
|
|
they are passed to the view. For example, this can be used to pop a
|
|
common language code value and place it in ``g`` rather than pass it to
|
|
every view.
|
|
|
|
The function is passed the endpoint name and values dict. The return
|
|
value is ignored.
|
|
"""
|
|
self.url_value_preprocessors[None].append(f)
|
|
return f
|
|
|
|
@setupmethod
|
|
def url_defaults(self, f: URLDefaultCallable) -> URLDefaultCallable:
|
|
"""Callback function for URL defaults for all view functions of the
|
|
application. It's called with the endpoint and values and should
|
|
update the values passed in place.
|
|
"""
|
|
self.url_default_functions[None].append(f)
|
|
return f
|
|
|
|
@setupmethod
|
|
def errorhandler(
|
|
self, code_or_exception: t.Union[t.Type[GenericException], int]
|
|
) -> t.Callable[
|
|
["ErrorHandlerCallable[GenericException]"],
|
|
"ErrorHandlerCallable[GenericException]",
|
|
]:
|
|
"""Register a function to handle errors by code or exception class.
|
|
|
|
A decorator that is used to register a function given an
|
|
error code. Example::
|
|
|
|
@app.errorhandler(404)
|
|
def page_not_found(error):
|
|
return 'This page does not exist', 404
|
|
|
|
You can also register handlers for arbitrary exceptions::
|
|
|
|
@app.errorhandler(DatabaseError)
|
|
def special_exception_handler(error):
|
|
return 'Database connection failed', 500
|
|
|
|
.. versionadded:: 0.7
|
|
Use :meth:`register_error_handler` instead of modifying
|
|
:attr:`error_handler_spec` directly, for application wide error
|
|
handlers.
|
|
|
|
.. versionadded:: 0.7
|
|
One can now additionally also register custom exception types
|
|
that do not necessarily have to be a subclass of the
|
|
:class:`~werkzeug.exceptions.HTTPException` class.
|
|
|
|
:param code_or_exception: the code as integer for the handler, or
|
|
an arbitrary exception
|
|
"""
|
|
|
|
def decorator(
|
|
f: "ErrorHandlerCallable[GenericException]",
|
|
) -> "ErrorHandlerCallable[GenericException]":
|
|
self.register_error_handler(code_or_exception, f)
|
|
return f
|
|
|
|
return decorator
|
|
|
|
@setupmethod
|
|
def register_error_handler(
|
|
self,
|
|
code_or_exception: t.Union[t.Type[GenericException], int],
|
|
f: "ErrorHandlerCallable[GenericException]",
|
|
) -> None:
|
|
"""Alternative error attach function to the :meth:`errorhandler`
|
|
decorator that is more straightforward to use for non decorator
|
|
usage.
|
|
|
|
.. versionadded:: 0.7
|
|
"""
|
|
if isinstance(code_or_exception, HTTPException): # old broken behavior
|
|
raise ValueError(
|
|
"Tried to register a handler for an exception instance"
|
|
f" {code_or_exception!r}. Handlers can only be"
|
|
" registered for exception classes or HTTP error codes."
|
|
)
|
|
|
|
try:
|
|
exc_class, code = self._get_exc_class_and_code(code_or_exception)
|
|
except KeyError:
|
|
raise KeyError(
|
|
f"'{code_or_exception}' is not a recognized HTTP error"
|
|
" code. Use a subclass of HTTPException with that code"
|
|
" instead."
|
|
) from None
|
|
|
|
self.error_handler_spec[None][code][exc_class] = t.cast(
|
|
"ErrorHandlerCallable[Exception]", f
|
|
)
|
|
|
|
@staticmethod
|
|
def _get_exc_class_and_code(
|
|
exc_class_or_code: t.Union[t.Type[Exception], int]
|
|
) -> t.Tuple[t.Type[Exception], t.Optional[int]]:
|
|
"""Get the exception class being handled. For HTTP status codes
|
|
or ``HTTPException`` subclasses, return both the exception and
|
|
status code.
|
|
|
|
:param exc_class_or_code: Any exception class, or an HTTP status
|
|
code as an integer.
|
|
"""
|
|
exc_class: t.Type[Exception]
|
|
if isinstance(exc_class_or_code, int):
|
|
exc_class = default_exceptions[exc_class_or_code]
|
|
else:
|
|
exc_class = exc_class_or_code
|
|
|
|
assert issubclass(
|
|
exc_class, Exception
|
|
), "Custom exceptions must be subclasses of Exception."
|
|
|
|
if issubclass(exc_class, HTTPException):
|
|
return exc_class, exc_class.code
|
|
else:
|
|
return exc_class, None
|
|
|
|
|
|
def _endpoint_from_view_func(view_func: t.Callable) -> str:
|
|
"""Internal helper that returns the default endpoint for a given
|
|
function. This always is the function name.
|
|
"""
|
|
assert view_func is not None, "expected view func if endpoint is not provided."
|
|
return view_func.__name__
|
|
|
|
|
|
def _matching_loader_thinks_module_is_package(loader, mod_name):
|
|
"""Attempt to figure out if the given name is a package or a module.
|
|
|
|
:param: loader: The loader that handled the name.
|
|
:param mod_name: The name of the package or module.
|
|
"""
|
|
# Use loader.is_package if it's available.
|
|
if hasattr(loader, "is_package"):
|
|
return loader.is_package(mod_name)
|
|
|
|
cls = type(loader)
|
|
|
|
# NamespaceLoader doesn't implement is_package, but all names it
|
|
# loads must be packages.
|
|
if cls.__module__ == "_frozen_importlib" and cls.__name__ == "NamespaceLoader":
|
|
return True
|
|
|
|
# Otherwise we need to fail with an error that explains what went
|
|
# wrong.
|
|
raise AttributeError(
|
|
f"'{cls.__name__}.is_package()' must be implemented for PEP 302"
|
|
f" import hooks."
|
|
)
|
|
|
|
|
|
def _find_package_path(root_mod_name):
|
|
"""Find the path that contains the package or module."""
|
|
try:
|
|
spec = importlib.util.find_spec(root_mod_name)
|
|
|
|
if spec is None:
|
|
raise ValueError("not found")
|
|
# ImportError: the machinery told us it does not exist
|
|
# ValueError:
|
|
# - the module name was invalid
|
|
# - the module name is __main__
|
|
# - *we* raised `ValueError` due to `spec` being `None`
|
|
except (ImportError, ValueError):
|
|
pass # handled below
|
|
else:
|
|
# namespace package
|
|
if spec.origin in {"namespace", None}:
|
|
return os.path.dirname(next(iter(spec.submodule_search_locations)))
|
|
# a package (with __init__.py)
|
|
elif spec.submodule_search_locations:
|
|
return os.path.dirname(os.path.dirname(spec.origin))
|
|
# just a normal module
|
|
else:
|
|
return os.path.dirname(spec.origin)
|
|
|
|
# we were unable to find the `package_path` using PEP 451 loaders
|
|
loader = pkgutil.get_loader(root_mod_name)
|
|
|
|
if loader is None or root_mod_name == "__main__":
|
|
# import name is not found, or interactive/main module
|
|
return os.getcwd()
|
|
|
|
if hasattr(loader, "get_filename"):
|
|
filename = loader.get_filename(root_mod_name)
|
|
elif hasattr(loader, "archive"):
|
|
# zipimporter's loader.archive points to the .egg or .zip file.
|
|
filename = loader.archive
|
|
else:
|
|
# At least one loader is missing both get_filename and archive:
|
|
# Google App Engine's HardenedModulesHook, use __file__.
|
|
filename = importlib.import_module(root_mod_name).__file__
|
|
|
|
package_path = os.path.abspath(os.path.dirname(filename))
|
|
|
|
# If the imported name is a package, filename is currently pointing
|
|
# to the root of the package, need to get the current directory.
|
|
if _matching_loader_thinks_module_is_package(loader, root_mod_name):
|
|
package_path = os.path.dirname(package_path)
|
|
|
|
return package_path
|
|
|
|
|
|
def find_package(import_name: str):
|
|
"""Find the prefix that a package is installed under, and the path
|
|
that it would be imported from.
|
|
|
|
The prefix is the directory containing the standard directory
|
|
hierarchy (lib, bin, etc.). If the package is not installed to the
|
|
system (:attr:`sys.prefix`) or a virtualenv (``site-packages``),
|
|
``None`` is returned.
|
|
|
|
The path is the entry in :attr:`sys.path` that contains the package
|
|
for import. If the package is not installed, it's assumed that the
|
|
package was imported from the current working directory.
|
|
"""
|
|
root_mod_name, _, _ = import_name.partition(".")
|
|
package_path = _find_package_path(root_mod_name)
|
|
py_prefix = os.path.abspath(sys.prefix)
|
|
|
|
# installed to the system
|
|
if package_path.startswith(py_prefix):
|
|
return py_prefix, package_path
|
|
|
|
site_parent, site_folder = os.path.split(package_path)
|
|
|
|
# installed to a virtualenv
|
|
if site_folder.lower() == "site-packages":
|
|
parent, folder = os.path.split(site_parent)
|
|
|
|
# Windows (prefix/lib/site-packages)
|
|
if folder.lower() == "lib":
|
|
return parent, package_path
|
|
|
|
# Unix (prefix/lib/pythonX.Y/site-packages)
|
|
if os.path.basename(parent).lower() == "lib":
|
|
return os.path.dirname(parent), package_path
|
|
|
|
# something else (prefix/site-packages)
|
|
return site_parent, package_path
|
|
|
|
# not installed
|
|
return None, package_path
|