:mod:`!importlib` --- The implementation of :keyword:`!import`

.. module:: importlib :synopsis: The implementation of the import machinery.

.. moduleauthor:: Brett Cannon [email protected] .. sectionauthor:: Brett Cannon [email protected]

.. versionadded:: 3.1

Source code: :source:Lib/importlib/__init__.py

Introduction

The purpose of the :mod:importlib package is two-fold. One is to provide the implementation of the :keyword:import statement (and thus, by extension, the :func:__import__ function) in Python source code. This provides an implementation of :keyword:!import which is portable to any Python interpreter. This also provides an implementation which is easier to comprehend than one implemented in a programming language other than Python.

Two, the components to implement :keyword:import are exposed in this package, making it easier for users to create their own custom objects (known generically as an :term:importer) to participate in the import process.

.. seealso::

:ref:`import`
    The language reference for the :keyword:`import` statement.

`Packages specification <https://www.python.org/doc/essays/packages/>`__
    Original specification of packages. Some semantics have changed since
    the writing of this document (e.g. redirecting based on ``None``
    in :data:`sys.modules`).

The :func:`.__import__` function
    The :keyword:`import` statement is syntactic sugar for this function.

:pep:`235`
    Import on Case-Insensitive Platforms

:pep:`263`
    Defining Python Source Code Encodings

:pep:`302`
    New Import Hooks

:pep:`328`
    Imports: Multi-Line and Absolute/Relative

:pep:`366`
    Main module explicit relative imports

:pep:`420`
    Implicit namespace packages

:pep:`451`
    A ModuleSpec Type for the Import System

:pep:`488`
    Elimination of PYO files

:pep:`489`
    Multi-phase extension module initialization

:pep:`552`
    Deterministic pycs

:pep:`3120`
    Using UTF-8 as the Default Source Encoding

:pep:`3147`
    PYC Repository Directories

Functions

.. function:: import(name, globals=None, locals=None, fromlist=(), level=0)

An implementation of the built-in :func:`__import__` function.

.. note::
   Programmatic importing of modules should use :func:`import_module`
   instead of this function.

.. function:: import_module(name, package=None)

Import a module. The *name* argument specifies what module to
import in absolute or relative terms
(e.g. either ``pkg.mod`` or ``..mod``). If the name is
specified in relative terms, then the *package* argument must be set to
the name of the package which is to act as the anchor for resolving the
package name (e.g. ``import_module('..mod', 'pkg.subpkg')`` will import
``pkg.mod``).

The :func:`import_module` function acts as a simplifying wrapper around
:func:`importlib.__import__`. This means all semantics of the function are
derived from :func:`importlib.__import__`. The most important difference
between these two functions is that :func:`import_module` returns the
specified package or module (e.g. ``pkg.mod``), while :func:`__import__`
returns the top-level package or module (e.g. ``pkg``).

If you are dynamically importing a module that was created since the
interpreter began execution (e.g., created a Python source file), you may
need to call :func:`invalidate_caches` in order for the new module to be
noticed by the import system.

.. versionchanged:: 3.3
   Parent packages are automatically imported.

.. function:: find_loader(name, path=None)

Find the loader for a module, optionally within the specified path. If the module is in :attr:sys.modules, then sys.modules[name].__loader__ is returned (unless the loader would be None or is not set, in which case :exc:ValueError is raised). Otherwise a search using :attr:sys.meta_path is done. None is returned if no loader is found.

A dotted name does not have its parents implicitly imported as that requires loading them and that may not be desired. To properly import a submodule you will need to import all parent packages of the submodule and use the correct argument to path.

.. versionadded:: 3.3

.. versionchanged:: 3.4 If __loader__ is not set, raise :exc:ValueError, just like when the attribute is set to None.

.. deprecated:: 3.4 Use :func:importlib.util.find_spec instead.

.. function:: invalidate_caches()

Invalidate the internal caches of finders stored at :data:sys.meta_path. If a finder implements invalidate_caches() then it will be called to perform the invalidation. This function should be called if any modules are created/installed while your program is running to guarantee all finders will notice the new module's existence.

.. versionadded:: 3.3

.. function:: reload(module)

Reload a previously imported module. The argument must be a module object, so it must have been successfully imported before. This is useful if you have edited the module source file using an external editor and want to try out the new version without leaving the Python interpreter. The return value is the module object (which can be different if re-importing causes a different object to be placed in :data:sys.modules).

When :func:reload is executed:

Python module's code is recompiled and the module-level code re-executed, defining a new set of objects which are bound to names in the module's dictionary by reusing the :term:loader which originally loaded the module. The init function of extension modules is not called a second time.
As with all other objects in Python the old objects are only reclaimed after their reference counts drop to zero.
The names in the module namespace are updated to point to any new or changed objects.
Other references to the old objects (such as names external to the module) are not rebound to refer to the new objects and must be updated in each namespace where they occur if that is desired.

There are a number of other caveats:

When a module is reloaded, its dictionary (containing the module's global variables) is retained. Redefinitions of names will override the old definitions, so this is generally not a problem. If the new version of a module does not define a name that was defined by the old version, the old definition remains. This feature can be used to the module's advantage if it maintains a global table or cache of objects --- with a :keyword:try statement it can test for the table's presence and skip its initialization if desired::

  try:
      cache
  except NameError:
      cache = {}

It is generally not very useful to reload built-in or dynamically loaded modules. Reloading :mod:sys, :mod:__main__, :mod:builtins and other key modules is not recommended. In many cases extension modules are not designed to be initialized more than once, and may fail in arbitrary ways when reloaded.

If a module imports objects from another module using :keyword:from ... :keyword:import ..., calling :func:reload for the other module does not redefine the objects imported from it --- one way around this is to re-execute the :keyword:!from statement, another is to use :keyword:!import and qualified names (module.name) instead.

If a module instantiates instances of a class, reloading the module that defines the class does not affect the method definitions of the instances --- they continue to use the old class definition. The same is true for derived classes.

.. versionadded:: 3.4 .. versionchanged:: 3.7 :exc:ModuleNotFoundError is raised when the module being reloaded lacks a :class:ModuleSpec.

:mod:`importlib.abc` -- Abstract base classes related to import

.. module:: importlib.abc :synopsis: Abstract base classes related to import

Source code: :source:Lib/importlib/abc.py

The :mod:importlib.abc module contains all of the core abstract base classes used by :keyword:import. Some subclasses of the core abstract base classes are also provided to help in implementing the core ABCs.

ABC hierarchy::

object
 +-- Finder (deprecated)
 |    +-- MetaPathFinder
 |    +-- PathEntryFinder
 +-- Loader
      +-- ResourceLoader --------+
      +-- InspectLoader          |
           +-- ExecutionLoader --+
                                 +-- FileLoader
                                 +-- SourceLoader

.. class:: Finder

An abstract base class representing a :term:finder.

.. deprecated:: 3.3 Use :class:MetaPathFinder or :class:PathEntryFinder instead.

.. abstractmethod:: find_module(fullname, path=None)

  An abstract method for finding a :term:`loader` for the specified
  module.  Originally specified in :pep:`302`, this method was meant
  for use in :data:`sys.meta_path` and in the path-based import subsystem.

  .. versionchanged:: 3.4
     Returns ``None`` when called instead of raising
     :exc:`NotImplementedError`.

.. class:: MetaPathFinder

An abstract base class representing a :term:meta path finder. For compatibility, this is a subclass of :class:Finder.

.. versionadded:: 3.3

.. method:: find_spec(fullname, path, target=None)

  An abstract method for finding a :term:`spec <module spec>` for
  the specified module.  If this is a top-level import, *path* will
  be ``None``.  Otherwise, this is a search for a subpackage or
  module and *path* will be the value of :attr:`__path__` from the
  parent package. If a spec cannot be found, ``None`` is returned.
  When passed in, ``target`` is a module object that the finder may
  use to make a more educated guess about what spec to return.

  .. versionadded:: 3.4

.. method:: find_module(fullname, path)

  A legacy method for finding a :term:`loader` for the specified
  module.  If this is a top-level import, *path* will be ``None``.
  Otherwise, this is a search for a subpackage or module and *path*
  will be the value of :attr:`__path__` from the parent
  package. If a loader cannot be found, ``None`` is returned.

  If :meth:`find_spec` is defined, backwards-compatible functionality is
  provided.

  .. versionchanged:: 3.4
     Returns ``None`` when called instead of raising
     :exc:`NotImplementedError`. Can use :meth:`find_spec` to provide
     functionality.

  .. deprecated:: 3.4
     Use :meth:`find_spec` instead.

.. method:: invalidate_caches()

  An optional method which, when called, should invalidate any internal
  cache used by the finder. Used by :func:`importlib.invalidate_caches`
  when invalidating the caches of all finders on :data:`sys.meta_path`.

  .. versionchanged:: 3.4
     Returns ``None`` when called instead of ``NotImplemented``.

.. class:: PathEntryFinder

An abstract base class representing a :term:path entry finder. Though it bears some similarities to :class:MetaPathFinder, PathEntryFinder is meant for use only within the path-based import subsystem provided by :class:PathFinder. This ABC is a subclass of :class:Finder for compatibility reasons only.

.. versionadded:: 3.3

.. method:: find_spec(fullname, target=None)

  An abstract method for finding a :term:`spec <module spec>` for
  the specified module.  The finder will search for the module only
  within the :term:`path entry` to which it is assigned.  If a spec
  cannot be found, ``None`` is returned.  When passed in, ``target``
  is a module object that the finder may use to make a more educated
  guess about what spec to return.

  .. versionadded:: 3.4

.. method:: find_loader(fullname)

  A legacy method for finding a :term:`loader` for the specified
  module.  Returns a 2-tuple of ``(loader, portion)`` where ``portion``
  is a sequence of file system locations contributing to part of a namespace
  package. The loader may be ``None`` while specifying ``portion`` to
  signify the contribution of the file system locations to a namespace
  package. An empty list can be used for ``portion`` to signify the loader
  is not part of a namespace package. If ``loader`` is ``None`` and
  ``portion`` is the empty list then no loader or location for a namespace
  package were found (i.e. failure to find anything for the module).

  If :meth:`find_spec` is defined then backwards-compatible functionality is
  provided.

  .. versionchanged:: 3.4
     Returns ``(None, [])`` instead of raising :exc:`NotImplementedError`.
     Uses :meth:`find_spec` when available to provide functionality.

  .. deprecated:: 3.4
     Use :meth:`find_spec` instead.

.. method:: find_module(fullname)

  A concrete implementation of :meth:`Finder.find_module` which is
  equivalent to ``self.find_loader(fullname)[0]``.

  .. deprecated:: 3.4
     Use :meth:`find_spec` instead.

.. method:: invalidate_caches()

  An optional method which, when called, should invalidate any internal
  cache used by the finder. Used by :meth:`PathFinder.invalidate_caches`
  when invalidating the caches of all cached finders.

.. class:: Loader

An abstract base class for a :term:`loader`.
See :pep:`302` for the exact definition for a loader.

Loaders that wish to support resource reading should implement a
``get_resource_reader(fullname)`` method as specified by
:class:`importlib.abc.ResourceReader`.

.. versionchanged:: 3.7
   Introduced the optional ``get_resource_reader()`` method.

.. method:: create_module(spec)

   A method that returns the module object to use when
   importing a module.  This method may return ``None``,
   indicating that default module creation semantics should take place.

   .. versionadded:: 3.4

   .. versionchanged:: 3.5
      Starting in Python 3.6, this method will not be optional when
      :meth:`exec_module` is defined.

.. method:: exec_module(module)

   An abstract method that executes the module in its own namespace
   when a module is imported or reloaded.  The module should already
   be initialized when ``exec_module()`` is called. When this method exists,
   :meth:`~importlib.abc.Loader.create_module` must be defined.

   .. versionadded:: 3.4

   .. versionchanged:: 3.6
      :meth:`~importlib.abc.Loader.create_module` must also be defined.

.. method:: load_module(fullname)

    A legacy method for loading a module. If the module cannot be
    loaded, :exc:`ImportError` is raised, otherwise the loaded module is
    returned.

    If the requested module already exists in :data:`sys.modules`, that
    module should be used and reloaded.
    Otherwise the loader should create a new module and insert it into
    :data:`sys.modules` before any loading begins, to prevent recursion
    from the import. If the loader inserted a module and the load fails, it
    must be removed by the loader from :data:`sys.modules`; modules already
    in :data:`sys.modules` before the loader began execution should be left
    alone (see :func:`importlib.util.module_for_loader`).

    The loader should set several attributes on the module.
    (Note that some of these attributes can change when a module is
    reloaded):

    - :attr:`__name__`
        The name of the module.

    - :attr:`__file__`
        The path to where the module data is stored (not set for built-in
        modules).

    - :attr:`__cached__`
        The path to where a compiled version of the module is/should be
        stored (not set when the attribute would be inappropriate).

    - :attr:`__path__`
        A list of strings specifying the search path within a
        package. This attribute is not set on modules.

    - :attr:`__package__`
        The parent package for the module/package. If the module is
        top-level then it has a value of the empty string. The
        :func:`importlib.util.module_for_loader` decorator can handle the
        details for :attr:`__package__`.

    - :attr:`__loader__`
        The loader used to load the module. The
        :func:`importlib.util.module_for_loader` decorator can handle the
        details for :attr:`__package__`.

    When :meth:`exec_module` is available then backwards-compatible
    functionality is provided.

    .. versionchanged:: 3.4
       Raise :exc:`ImportError` when called instead of
       :exc:`NotImplementedError`. Functionality provided when
       :meth:`exec_module` is available.

    .. deprecated:: 3.4
       The recommended API for loading a module is :meth:`exec_module`
       (and :meth:`create_module`).  Loaders should implement
       it instead of load_module().  The import machinery takes care of
       all the other responsibilities of load_module() when exec_module()
       is implemented.

.. method:: module_repr(module)

    A legacy method which when implemented calculates and returns the
    given module's repr, as a string. The module type's default repr() will
    use the result of this method as appropriate.

    .. versionadded:: 3.3

    .. versionchanged:: 3.4
       Made optional instead of an abstractmethod.

    .. deprecated:: 3.4
       The import machinery now takes care of this automatically.

.. class:: ResourceReader

An :term:`abstract base class` to provide the ability to read
*resources*.

From the perspective of this ABC, a *resource* is a binary
artifact that is shipped within a package. Typically this is
something like a data file that lives next to the ``__init__.py``
file of the package. The purpose of this class is to help abstract
out the accessing of such data files so that it does not matter if
the package and its data file(s) are stored in a e.g. zip file
versus on the file system.

For any of methods of this class, a *resource* argument is
expected to be a :term:`path-like object` which represents
conceptually just a file name. This means that no subdirectory
paths should be included in the *resource* argument. This is
because the location of the package the reader is for, acts as the
"directory". Hence the metaphor for directories and file
names is packages and resources, respectively. This is also why
instances of this class are expected to directly correlate to
a specific package (instead of potentially representing multiple
packages or a module).

Loaders that wish to support resource reading are expected to
provide a method called ``get_resource_loader(fullname)`` which
returns an object implementing this ABC's interface. If the module
specified by fullname is not a package, this method should return
:const:`None`. An object compatible with this ABC should only be
returned when the specified module is a package.

.. versionadded:: 3.7

.. abstractmethod:: open_resource(resource)

    Returns an opened, :term:`file-like object` for binary reading
    of the *resource*.

    If the resource cannot be found, :exc:`FileNotFoundError` is
    raised.

.. abstractmethod:: resource_path(resource)

    Returns the file system path to the *resource*.

    If the resource does not concretely exist on the file system,
    raise :exc:`FileNotFoundError`.

.. abstractmethod:: is_resource(name)

    Returns ``True`` if the named *name* is considered a resource.
    :exc:`FileNotFoundError` is raised if *name* does not exist.

.. abstractmethod:: contents()

    Returns an :term:`iterable` of strings over the contents of
    the package. Do note that it is not required that all names
    returned by the iterator be actual resources, e.g. it is
    acceptable to return names for which :meth:`is_resource` would
    be false.

    Allowing non-resource names to be returned is to allow for
    situations where how a package and its resources are stored
    are known a priori and the non-resource names would be useful.
    For instance, returning subdirectory names is allowed so that
    when it is known that the package and resources are stored on
    the file system then those subdirectory names can be used
    directly.

    The abstract method returns an iterable of no items.

.. class:: ResourceLoader

An abstract base class for a :term:`loader` which implements the optional
:pep:`302` protocol for loading arbitrary resources from the storage
back-end.

.. deprecated:: 3.7
   This ABC is deprecated in favour of supporting resource loading
   through :class:`importlib.abc.ResourceReader`.

.. abstractmethod:: get_data(path)

    An abstract method to return the bytes for the data located at *path*.
    Loaders that have a file-like storage back-end
    that allows storing arbitrary data
    can implement this abstract method to give direct access
    to the data stored. :exc:`OSError` is to be raised if the *path* cannot
    be found. The *path* is expected to be constructed using a module's
    :attr:`__file__` attribute or an item from a package's :attr:`__path__`.

    .. versionchanged:: 3.4
       Raises :exc:`OSError` instead of :exc:`NotImplementedError`.

.. class:: InspectLoader

An abstract base class for a :term:`loader` which implements the optional
:pep:`302` protocol for loaders that inspect modules.

.. method:: get_code(fullname)

    Return the code object for a module, or ``None`` if the module does not
    have a code object (as would be the case, for example, for a built-in
    module).  Raise an :exc:`ImportError` if loader cannot find the
    requested module.

    .. note::
       While the method has a default implementation, it is suggested that
       it be overridden if possible for performance.

    .. index::
       single: universal newlines; importlib.abc.InspectLoader.get_source method

    .. versionchanged:: 3.4
       No longer abstract and a concrete implementation is provided.

.. abstractmethod:: get_source(fullname)

    An abstract method to return the source of a module. It is returned as
    a text string using :term:`universal newlines`, translating all
    recognized line separators into ``'\n'`` characters.  Returns ``None``
    if no source is available (e.g. a built-in module). Raises
    :exc:`ImportError` if the loader cannot find the module specified.

    .. versionchanged:: 3.4
       Raises :exc:`ImportError` instead of :exc:`NotImplementedError`.

.. method:: is_package(fullname)

    An abstract method to return a true value if the module is a package, a
    false value otherwise. :exc:`ImportError` is raised if the
    :term:`loader` cannot find the module.

    .. versionchanged:: 3.4
       Raises :exc:`ImportError` instead of :exc:`NotImplementedError`.

.. staticmethod:: source_to_code(data, path='<string>')

    Create a code object from Python source.

    The *data* argument can be whatever the :func:`compile` function
    supports (i.e. string or bytes). The *path* argument should be
    the "path" to where the source code originated from, which can be an
    abstract concept (e.g. location in a zip file).

    With the subsequent code object one can execute it in a module by
    running ``exec(code, module.__dict__)``.

    .. versionadded:: 3.4

    .. versionchanged:: 3.5
       Made the method static.

.. method:: exec_module(module)

   Implementation of :meth:`Loader.exec_module`.

   .. versionadded:: 3.4

.. method:: load_module(fullname)

   Implementation of :meth:`Loader.load_module`.

   .. deprecated:: 3.4
      use :meth:`exec_module` instead.

.. class:: ExecutionLoader

An abstract base class which inherits from :class:`InspectLoader` that,
when implemented, helps a module to be executed as a script. The ABC
represents an optional :pep:`302` protocol.

.. abstractmethod:: get_filename(fullname)

    An abstract method that is to return the value of :attr:`__file__` for
    the specified module. If no path is available, :exc:`ImportError` is
    raised.

    If source code is available, then the method should return the path to
    the source file, regardless of whether a bytecode was used to load the
    module.

    .. versionchanged:: 3.4
       Raises :exc:`ImportError` instead of :exc:`NotImplementedError`.

.. class:: FileLoader(fullname, path)

An abstract base class which inherits from :class:ResourceLoader and :class:ExecutionLoader, providing concrete implementations of :meth:ResourceLoader.get_data and :meth:ExecutionLoader.get_filename.

The fullname argument is a fully resolved name of the module the loader is to handle. The path argument is the path to the file for the module.

.. versionadded:: 3.3

.. attribute:: name

  The name of the module the loader can handle.

.. attribute:: path

  Path to the file of the module.

.. method:: load_module(fullname)

  Calls super's ``load_module()``.

  .. deprecated:: 3.4
     Use :meth:`Loader.exec_module` instead.

.. abstractmethod:: get_filename(fullname)

  Returns :attr:`path`.

.. abstractmethod:: get_data(path)

  Reads *path* as a binary file and returns the bytes from it.

.. class:: SourceLoader

An abstract base class for implementing source (and optionally bytecode)
file loading. The class inherits from both :class:`ResourceLoader` and
:class:`ExecutionLoader`, requiring the implementation of:

* :meth:`ResourceLoader.get_data`
* :meth:`ExecutionLoader.get_filename`
      Should only return the path to the source file; sourceless
      loading is not supported.

The abstract methods defined by this class are to add optional bytecode
file support. Not implementing these optional methods (or causing them to
raise :exc:`NotImplementedError`) causes the loader to
only work with source code. Implementing the methods allows the loader to
work with source *and* bytecode files; it does not allow for *sourceless*
loading where only bytecode is provided.  Bytecode files are an
optimization to speed up loading by removing the parsing step of Python's
compiler, and so no bytecode-specific API is exposed.

.. method:: path_stats(path)

    Optional abstract method which returns a :class:`dict` containing
    metadata about the specified path.  Supported dictionary keys are:

    - ``'mtime'`` (mandatory): an integer or floating-point number
      representing the modification time of the source code;
    - ``'size'`` (optional): the size in bytes of the source code.

    Any other keys in the dictionary are ignored, to allow for future
    extensions. If the path cannot be handled, :exc:`OSError` is raised.

    .. versionadded:: 3.3

    .. versionchanged:: 3.4
       Raise :exc:`OSError` instead of :exc:`NotImplementedError`.

.. method:: path_mtime(path)

    Optional abstract method which returns the modification time for the
    specified path.

    .. deprecated:: 3.3
       This method is deprecated in favour of :meth:`path_stats`.  You don't
       have to implement it, but it is still available for compatibility
       purposes. Raise :exc:`OSError` if the path cannot be handled.

    .. versionchanged:: 3.4
       Raise :exc:`OSError` instead of :exc:`NotImplementedError`.

.. method:: set_data(path, data)

    Optional abstract method which writes the specified bytes to a file
    path. Any intermediate directories which do not exist are to be created
    automatically.

    When writing to the path fails because the path is read-only
    (:attr:`errno.EACCES`/:exc:`PermissionError`), do not propagate the
    exception.

    .. versionchanged:: 3.4
       No longer raises :exc:`NotImplementedError` when called.

.. method:: get_code(fullname)

    Concrete implementation of :meth:`InspectLoader.get_code`.

.. method:: exec_module(module)

   Concrete implementation of :meth:`Loader.exec_module`.

   .. versionadded:: 3.4

.. method:: load_module(fullname)

   Concrete implementation of :meth:`Loader.load_module`.

   .. deprecated:: 3.4
      Use :meth:`exec_module` instead.

.. method:: get_source(fullname)

    Concrete implementation of :meth:`InspectLoader.get_source`.

.. method:: is_package(fullname)

    Concrete implementation of :meth:`InspectLoader.is_package`. A module
    is determined to be a package if its file path (as provided by
    :meth:`ExecutionLoader.get_filename`) is a file named
    ``__init__`` when the file extension is removed **and** the module name
    itself does not end in ``__init__``.

:mod:`importlib.resources` -- Resources

.. module:: importlib.resources :synopsis: Package resource reading, opening, and access

Source code: :source:Lib/importlib/resources.py

.. versionadded:: 3.7

This module leverages Python's import system to provide access to resources within packages. If you can import a package, you can access resources within that package. Resources can be opened or read, in either binary or text mode.

Resources are roughly akin to files inside directories, though it's important to keep in mind that this is just a metaphor. Resources and packages do not have to exist as physical files and directories on the file system.

.. note::

This module provides functionality similar to pkg_resources <https://setuptools.readthedocs.io/en/latest/pkg_resources.html>_ Basic Resource Access <http://setuptools.readthedocs.io/en/latest/pkg_resources.html#basic-resource-access>_ without the performance overhead of that package. This makes reading resources included in packages easier, with more stable and consistent semantics.

The standalone backport of this module provides more information on using importlib.resources <http://importlib-resources.readthedocs.io/en/latest/using.html>_ and migrating from pkg_resources to importlib.resources <http://importlib-resources.readthedocs.io/en/latest/migration.html>_.

Loaders that wish to support resource reading should implement a get_resource_reader(fullname) method as specified by :class:importlib.abc.ResourceReader.

The following types are defined.

.. data:: Package

The ``Package`` type is defined as ``Union[str, ModuleType]``.  This means
that where the function describes accepting a ``Package``, you can pass in
either a string or a module.  Module objects must have a resolvable
``__spec__.submodule_search_locations`` that is not ``None``.

.. data:: Resource

This type describes the resource names passed into the various functions
in this package.  This is defined as ``Union[str, os.PathLike]``.

The following functions are available.

.. function:: open_binary(package, resource)

Open for binary reading the *resource* within *package*.

*package* is either a name or a module object which conforms to the
``Package`` requirements.  *resource* is the name of the resource to open
within *package*; it may not contain path separators and it may not have
sub-resources (i.e. it cannot be a directory).  This function returns a
``typing.BinaryIO`` instance, a binary I/O stream open for reading.

.. function:: open_text(package, resource, encoding='utf-8', errors='strict')

Open for text reading the *resource* within *package*.  By default, the
resource is opened for reading as UTF-8.

*package* is either a name or a module object which conforms to the
``Package`` requirements.  *resource* is the name of the resource to open
within *package*; it may not contain path separators and it may not have
sub-resources (i.e. it cannot be a directory).  *encoding* and *errors*
have the same meaning as with built-in :func:`open`.

This function returns a ``typing.TextIO`` instance, a text I/O stream open
for reading.

.. function:: read_binary(package, resource)

Read and return the contents of the *resource* within *package* as
``bytes``.

*package* is either a name or a module object which conforms to the
``Package`` requirements.  *resource* is the name of the resource to open
within *package*; it may not contain path separators and it may not have
sub-resources (i.e. it cannot be a directory).  This function returns the
contents of the resource as :class:`bytes`.

.. function:: read_text(package, resource, encoding='utf-8', errors='strict')

Read and return the contents of *resource* within *package* as a ``str``.
By default, the contents are read as strict UTF-8.

*package* is either a name or a module object which conforms to the
``Package`` requirements.  *resource* is the name of the resource to open
within *package*; it may not contain path separators and it may not have
sub-resources (i.e. it cannot be a directory).  *encoding* and *errors*
have the same meaning as with built-in :func:`open`.  This function
returns the contents of the resource as :class:`str`.

.. function:: path(package, resource)

Return the path to the *resource* as an actual file system path.  This
function returns a context manager for use in a :keyword:`with` statement.
The context manager provides a :class:`pathlib.Path` object.

Exiting the context manager cleans up any temporary file created when the
resource needs to be extracted from e.g. a zip file.

*package* is either a name or a module object which conforms to the
``Package`` requirements.  *resource* is the name of the resource to open
within *package*; it may not contain path separators and it may not have
sub-resources (i.e. it cannot be a directory).

.. function:: is_resource(package, name)

Return ``True`` if there is a resource named *name* in the package,
otherwise ``False``.  Remember that directories are *not* resources!
*package* is either a name or a module object which conforms to the
``Package`` requirements.

.. function:: contents(package)

Return an iterable over the named items within the package.  The iterable
returns :class:`str` resources (e.g. files) and non-resources
(e.g. directories).  The iterable does not recurse into subdirectories.

*package* is either a name or a module object which conforms to the
``Package`` requirements.

:mod:`importlib.machinery` -- Importers and path hooks

.. module:: importlib.machinery :synopsis: Importers and path hooks

Source code: :source:Lib/importlib/machinery.py

This module contains the various objects that help :keyword:import find and load modules.

.. attribute:: SOURCE_SUFFIXES

A list of strings representing the recognized file suffixes for source modules.

.. versionadded:: 3.3

.. attribute:: DEBUG_BYTECODE_SUFFIXES

A list of strings representing the file suffixes for non-optimized bytecode modules.

.. versionadded:: 3.3

.. deprecated:: 3.5 Use :attr:BYTECODE_SUFFIXES instead.

.. attribute:: OPTIMIZED_BYTECODE_SUFFIXES

A list of strings representing the file suffixes for optimized bytecode modules.

.. versionadded:: 3.3

.. deprecated:: 3.5 Use :attr:BYTECODE_SUFFIXES instead.

.. attribute:: BYTECODE_SUFFIXES

A list of strings representing the recognized file suffixes for bytecode modules (including the leading dot).

.. versionadded:: 3.3

.. versionchanged:: 3.5 The value is no longer dependent on __debug__.

.. attribute:: EXTENSION_SUFFIXES

A list of strings representing the recognized file suffixes for extension modules.

.. versionadded:: 3.3

.. function:: all_suffixes()

Returns a combined list of strings representing all file suffixes for modules recognized by the standard import machinery. This is a helper for code which simply needs to know if a filesystem path potentially refers to a module without needing any details on the kind of module (for example, :func:inspect.getmodulename).

.. versionadded:: 3.3

.. class:: BuiltinImporter

An :term:`importer` for built-in modules. All known built-in modules are
listed in :data:`sys.builtin_module_names`. This class implements the
:class:`importlib.abc.MetaPathFinder` and
:class:`importlib.abc.InspectLoader` ABCs.

Only class methods are defined by this class to alleviate the need for
instantiation.

.. versionchanged:: 3.5
   As part of :pep:`489`, the builtin importer now implements
   :meth:`Loader.create_module` and :meth:`Loader.exec_module`

.. class:: FrozenImporter

An :term:`importer` for frozen modules. This class implements the
:class:`importlib.abc.MetaPathFinder` and
:class:`importlib.abc.InspectLoader` ABCs.

Only class methods are defined by this class to alleviate the need for
instantiation.

.. class:: WindowsRegistryFinder

:term:Finder for modules declared in the Windows registry. This class implements the :class:importlib.abc.MetaPathFinder ABC.

Only class methods are defined by this class to alleviate the need for instantiation.

.. versionadded:: 3.3

.. deprecated:: 3.6 Use :mod:site configuration instead. Future versions of Python may not enable this finder by default.

.. class:: PathFinder

A :term:Finder for :data:sys.path and package __path__ attributes. This class implements the :class:importlib.abc.MetaPathFinder ABC.

Only class methods are defined by this class to alleviate the need for instantiation.

.. classmethod:: find_spec(fullname, path=None, target=None)

  Class method that attempts to find a :term:`spec <module spec>`
  for the module specified by *fullname* on :data:`sys.path` or, if
  defined, on *path*. For each path entry that is searched,
  :data:`sys.path_importer_cache` is checked. If a non-false object
  is found then it is used as the :term:`path entry finder` to look
  for the module being searched for. If no entry is found in
  :data:`sys.path_importer_cache`, then :data:`sys.path_hooks` is
  searched for a finder for the path entry and, if found, is stored
  in :data:`sys.path_importer_cache` along with being queried about
  the module. If no finder is ever found then ``None`` is both
  stored in the cache and returned.

  .. versionadded:: 3.4

  .. versionchanged:: 3.5
     If the current working directory -- represented by an empty string --
     is no longer valid then ``None`` is returned but no value is cached
     in :data:`sys.path_importer_cache`.

.. classmethod:: find_module(fullname, path=None)

  A legacy wrapper around :meth:`find_spec`.

  .. deprecated:: 3.4
     Use :meth:`find_spec` instead.

.. classmethod:: invalidate_caches()

  Calls :meth:`importlib.abc.PathEntryFinder.invalidate_caches` on all
  finders stored in :data:`sys.path_importer_cache` that define the method.
  Otherwise entries in :data:`sys.path_importer_cache` set to ``None`` are
  deleted.

  .. versionchanged:: 3.7
     Entries of ``None`` in :data:`sys.path_importer_cache` are deleted.

.. versionchanged:: 3.4 Calls objects in :data:sys.path_hooks with the current working directory for '' (i.e. the empty string).

.. class:: FileFinder(path, *loader_details)

A concrete implementation of :class:importlib.abc.PathEntryFinder which caches results from the file system.

The path argument is the directory for which the finder is in charge of searching.

The loader_details argument is a variable number of 2-item tuples each containing a loader and a sequence of file suffixes the loader recognizes. The loaders are expected to be callables which accept two arguments of the module's name and the path to the file found.

The finder will cache the directory contents as necessary, making stat calls for each module search to verify the cache is not outdated. Because cache staleness relies upon the granularity of the operating system's state information of the file system, there is a potential race condition of searching for a module, creating a new file, and then searching for the module the new file represents. If the operations happen fast enough to fit within the granularity of stat calls, then the module search will fail. To prevent this from happening, when you create a module dynamically, make sure to call :func:importlib.invalidate_caches.

.. versionadded:: 3.3

.. attribute:: path

  The path the finder will search in.

.. method:: find_spec(fullname, target=None)

  Attempt to find the spec to handle *fullname* within :attr:`path`.

  .. versionadded:: 3.4

.. method:: find_loader(fullname)

  Attempt to find the loader to handle *fullname* within :attr:`path`.

.. method:: invalidate_caches()

  Clear out the internal cache.

.. classmethod:: path_hook(*loader_details)

  A class method which returns a closure for use on :attr:`sys.path_hooks`.
  An instance of :class:`FileFinder` is returned by the closure using the
  path argument given to the closure directly and *loader_details*
  indirectly.

  If the argument to the closure is not an existing directory,
  :exc:`ImportError` is raised.

.. class:: SourceFileLoader(fullname, path)

A concrete implementation of :class:importlib.abc.SourceLoader by subclassing :class:importlib.abc.FileLoader and providing some concrete implementations of other methods.

.. versionadded:: 3.3

.. attribute:: name

  The name of the module that this loader will handle.

.. attribute:: path

  The path to the source file.

.. method:: is_package(fullname)

  Return true if :attr:`path` appears to be for a package.

.. method:: path_stats(path)

  Concrete implementation of :meth:`importlib.abc.SourceLoader.path_stats`.

.. method:: set_data(path, data)

  Concrete implementation of :meth:`importlib.abc.SourceLoader.set_data`.

.. method:: load_module(name=None)

  Concrete implementation of :meth:`importlib.abc.Loader.load_module` where
  specifying the name of the module to load is optional.

  .. deprecated:: 3.6

     Use :meth:`importlib.abc.Loader.exec_module` instead.

.. class:: SourcelessFileLoader(fullname, path)

A concrete implementation of :class:importlib.abc.FileLoader which can import bytecode files (i.e. no source code files exist).

Please note that direct use of bytecode files (and thus not source code files) inhibits your modules from being usable by all Python implementations or new versions of Python which change the bytecode format.

.. versionadded:: 3.3

.. attribute:: name

  The name of the module the loader will handle.

.. attribute:: path

  The path to the bytecode file.

.. method:: is_package(fullname)

  Determines if the module is a package based on :attr:`path`.

.. method:: get_code(fullname)

  Returns the code object for :attr:`name` created from :attr:`path`.

.. method:: get_source(fullname)

  Returns ``None`` as bytecode files have no source when this loader is
  used.

.. method:: load_module(name=None)

Concrete implementation of :meth:importlib.abc.Loader.load_module where specifying the name of the module to load is optional.

.. deprecated:: 3.6

  Use :meth:`importlib.abc.Loader.exec_module` instead.

.. class:: ExtensionFileLoader(fullname, path)

A concrete implementation of :class:importlib.abc.ExecutionLoader for extension modules.

The fullname argument specifies the name of the module the loader is to support. The path argument is the path to the extension module's file.

.. versionadded:: 3.3

.. attribute:: name

  Name of the module the loader supports.

.. attribute:: path

  Path to the extension module.

.. method:: create_module(spec)

  Creates the module object from the given specification in accordance
  with :pep:`489`.

  .. versionadded:: 3.5

.. method:: exec_module(module)

  Initializes the given module object in accordance with :pep:`489`.

  .. versionadded:: 3.5

.. method:: is_package(fullname)

  Returns ``True`` if the file path points to a package's ``__init__``
  module based on :attr:`EXTENSION_SUFFIXES`.

.. method:: get_code(fullname)

  Returns ``None`` as extension modules lack a code object.

.. method:: get_source(fullname)

  Returns ``None`` as extension modules do not have source code.

.. method:: get_filename(fullname)

  Returns :attr:`path`.

  .. versionadded:: 3.4

.. class:: ModuleSpec(name, loader, *, origin=None, loader_state=None, is_package=None)

A specification for a module's import-system-related state. This is typically exposed as the module's __spec__ attribute. In the descriptions below, the names in parentheses give the corresponding attribute available directly on the module object. E.g. module.__spec__.origin == module.__file__. Note however that while the values are usually equivalent, they can differ since there is no synchronization between the two objects. Thus it is possible to update the module's __path__ at runtime, and this will not be automatically reflected in __spec__.submodule_search_locations.

.. versionadded:: 3.4

.. attribute:: name

(__name__)

A string for the fully-qualified name of the module.

.. attribute:: loader

(__loader__)

The loader to use for loading. For namespace packages this should be set to None.

.. attribute:: origin

(__file__)

Name of the place from which the module is loaded, e.g. "builtin" for built-in modules and the filename for modules loaded from source. Normally "origin" should be set, but it may be None (the default) which indicates it is unspecified (e.g. for namespace packages).

.. attribute:: submodule_search_locations

(__path__)

List of strings for where to find submodules, if a package (None otherwise).

.. attribute:: loader_state

Container of extra module-specific data for use during loading (or None).

.. attribute:: cached

(__cached__)

String for where the compiled module should be stored (or None).

.. attribute:: parent

(__package__)

(Read-only) Fully-qualified name of the package to which the module belongs as a submodule (or None).

.. attribute:: has_location

Boolean indicating whether or not the module's "origin" attribute refers to a loadable location.

:mod:`importlib.util` -- Utility code for importers

.. module:: importlib.util :synopsis: Utility code for importers

Source code: :source:Lib/importlib/util.py

This module contains the various objects that help in the construction of an :term:importer.

.. attribute:: MAGIC_NUMBER

The bytes which represent the bytecode version number. If you need help with loading/writing bytecode then consider :class:importlib.abc.SourceLoader.

.. versionadded:: 3.4

.. function:: cache_from_source(path, debug_override=None, *, optimization=None)

Return the :pep:3147/:pep:488 path to the byte-compiled file associated with the source path. For example, if path is /foo/bar/baz.py the return value would be /foo/bar/__pycache__/baz.cpython-32.pyc for Python 3.2. The cpython-32 string comes from the current magic tag (see :func:get_tag; if :attr:sys.implementation.cache_tag is not defined then :exc:NotImplementedError will be raised).

The optimization parameter is used to specify the optimization level of the bytecode file. An empty string represents no optimization, so /foo/bar/baz.py with an optimization of '' will result in a bytecode path of /foo/bar/__pycache__/baz.cpython-32.pyc. None causes the interpter's optimization level to be used. Any other value's string representation being used, so /foo/bar/baz.py with an optimization of 2 will lead to the bytecode path of /foo/bar/__pycache__/baz.cpython-32.opt-2.pyc. The string representation of optimization can only be alphanumeric, else :exc:ValueError is raised.

The debug_override parameter is deprecated and can be used to override the system's value for __debug__. A True value is the equivalent of setting optimization to the empty string. A False value is the same as setting optimization to 1. If both debug_override an optimization are not None then :exc:TypeError is raised.

.. versionadded:: 3.4

.. versionchanged:: 3.5 The optimization parameter was added and the debug_override parameter was deprecated.

.. versionchanged:: 3.6 Accepts a :term:path-like object.

.. function:: source_from_cache(path)

Given the path to a :pep:3147 file name, return the associated source code file path. For example, if path is /foo/bar/__pycache__/baz.cpython-32.pyc the returned path would be /foo/bar/baz.py. path need not exist, however if it does not conform to :pep:3147 or :pep:488 format, a :exc:ValueError is raised. If :attr:sys.implementation.cache_tag is not defined, :exc:NotImplementedError is raised.

.. versionadded:: 3.4

.. versionchanged:: 3.6 Accepts a :term:path-like object.

.. function:: decode_source(source_bytes)

Decode the given bytes representing source code and return it as a string with universal newlines (as required by :meth:importlib.abc.InspectLoader.get_source).

.. versionadded:: 3.4

.. function:: resolve_name(name, package)

Resolve a relative module name to an absolute one.

If name has no leading dots, then name is simply returned. This allows for usage such as importlib.util.resolve_name('sys', __package__) without doing a check to see if the package argument is needed.

:exc:ValueError is raised if name is a relative module name but package is a false value (e.g. None or the empty string). :exc:ValueError is also raised a relative name would escape its containing package (e.g. requesting ..bacon from within the spam package).

.. versionadded:: 3.3

.. function:: find_spec(name, package=None)

Find the :term:spec <module spec> for a module, optionally relative to the specified package name. If the module is in :attr:sys.modules, then sys.modules[name].__spec__ is returned (unless the spec would be None or is not set, in which case :exc:ValueError is raised). Otherwise a search using :attr:sys.meta_path is done. None is returned if no spec is found.

If name is for a submodule (contains a dot), the parent module is automatically imported.

name and package work the same as for :func:import_module.

.. versionadded:: 3.4

.. versionchanged:: 3.7 Raises :exc:ModuleNotFoundError instead of :exc:AttributeError if package is in fact not a package (i.e. lacks a :attr:__path__ attribute).

.. function:: module_from_spec(spec)

Create a new module based on spec and :meth:spec.loader.create_module <importlib.abc.Loader.create_module>.

If :meth:spec.loader.create_module <importlib.abc.Loader.create_module> does not return None, then any pre-existing attributes will not be reset. Also, no :exc:AttributeError will be raised if triggered while accessing spec or setting an attribute on the module.

This function is preferred over using :class:types.ModuleType to create a new module as spec is used to set as many import-controlled attributes on the module as possible.

.. versionadded:: 3.5

.. decorator:: module_for_loader

A :term:`decorator` for :meth:`importlib.abc.Loader.load_module`
to handle selecting the proper
module object to load with. The decorated method is expected to have a call
signature taking two positional arguments
(e.g. ``load_module(self, module)``) for which the second argument
will be the module **object** to be used by the loader.
Note that the decorator will not work on static methods because of the
assumption of two arguments.

The decorated method will take in the **name** of the module to be loaded
as expected for a :term:`loader`. If the module is not found in
:data:`sys.modules` then a new one is constructed. Regardless of where the
module came from, :attr:`__loader__` set to **self** and :attr:`__package__`
is set based on what :meth:`importlib.abc.InspectLoader.is_package` returns
(if available). These attributes are set unconditionally to support
reloading.

If an exception is raised by the decorated method and a module was added to
:data:`sys.modules`, then the module will be removed to prevent a partially
initialized module from being in left in :data:`sys.modules`. If the module
was already in :data:`sys.modules` then it is left alone.

.. versionchanged:: 3.3
   :attr:`__loader__` and :attr:`__package__` are automatically set
   (when possible).

.. versionchanged:: 3.4
   Set :attr:`__name__`, :attr:`__loader__` :attr:`__package__`
   unconditionally to support reloading.

.. deprecated:: 3.4
   The import machinery now directly performs all the functionality
   provided by this function.

.. decorator:: set_loader

A :term:decorator for :meth:importlib.abc.Loader.load_module to set the :attr:__loader__ attribute on the returned module. If the attribute is already set the decorator does nothing. It is assumed that the first positional argument to the wrapped method (i.e. self) is what :attr:__loader__ should be set to.

.. versionchanged:: 3.4 Set __loader__ if set to None, as if the attribute does not exist.

.. deprecated:: 3.4 The import machinery takes care of this automatically.

.. decorator:: set_package

A :term:decorator for :meth:importlib.abc.Loader.load_module to set the :attr:__package__ attribute on the returned module. If :attr:__package__ is set and has a value other than None it will not be changed.

.. deprecated:: 3.4 The import machinery takes care of this automatically.

.. function:: spec_from_loader(name, loader, *, origin=None, is_package=None)

A factory function for creating a :class:ModuleSpec instance based on a loader. The parameters have the same meaning as they do for ModuleSpec. The function uses available :term:loader APIs, such as :meth:InspectLoader.is_package, to fill in any missing information on the spec.

.. versionadded:: 3.4

.. function:: spec_from_file_location(name, location, *, loader=None, submodule_search_locations=None)

A factory function for creating a :class:ModuleSpec instance based on the path to a file. Missing information will be filled in on the spec by making use of loader APIs and by the implication that the module will be file-based.

.. versionadded:: 3.4

.. versionchanged:: 3.6 Accepts a :term:path-like object.

.. function:: source_hash(source_bytes)

Return the hash of source_bytes as bytes. A hash-based .pyc file embeds the :func:source_hash of the corresponding source file's contents in its header.

.. versionadded:: 3.7

.. class:: LazyLoader(loader)

A class which postpones the execution of the loader of a module until the module has an attribute accessed.

This class only works with loaders that define :meth:~importlib.abc.Loader.exec_module as control over what module type is used for the module is required. For those same reasons, the loader's :meth:~importlib.abc.Loader.create_module method must return None or a type for which its __class__ attribute can be mutated along with not using :term:slots <__slots__>. Finally, modules which substitute the object placed into :attr:sys.modules will not work as there is no way to properly replace the module references throughout the interpreter safely; :exc:ValueError is raised if such a substitution is detected.

.. note:: For projects where startup time is critical, this class allows for potentially minimizing the cost of loading a module if it is never used. For projects where startup time is not essential then use of this class is heavily discouraged due to error messages created during loading being postponed and thus occurring out of context.

.. versionadded:: 3.5

.. versionchanged:: 3.6 Began calling :meth:~importlib.abc.Loader.create_module, removing the compatibility warning for :class:importlib.machinery.BuiltinImporter and :class:importlib.machinery.ExtensionFileLoader.

.. classmethod:: factory(loader)

  A static method which returns a callable that creates a lazy loader. This
  is meant to be used in situations where the loader is passed by class
  instead of by instance.
  ::

    suffixes = importlib.machinery.SOURCE_SUFFIXES
    loader = importlib.machinery.SourceFileLoader
    lazy_loader = importlib.util.LazyLoader.factory(loader)
    finder = importlib.machinery.FileFinder(path, (lazy_loader, suffixes))

.. _importlib-examples:

Examples

Importing programmatically ''''''''''''''''''''''''''

To programmatically import a module, use :func:importlib.import_module. ::

import importlib

itertools = importlib.import_module('itertools')

Checking if a module can be imported ''''''''''''''''''''''''''''''''''''

If you need to find out if a module can be imported without actually doing the import, then you should use :func:importlib.util.find_spec. ::

import importlib.util import sys

For illustrative purposes.

name = 'itertools'

spec = importlib.util.find_spec(name) if spec is None: print("can't find the itertools module") else: # If you chose to perform the actual import ... module = importlib.util.module_from_spec(spec) spec.loader.exec_module(module) # Adding the module to sys.modules is optional. sys.modules[name] = module

Importing a source file directly ''''''''''''''''''''''''''''''''

To import a Python source file directly, use the following recipe (Python 3.5 and newer only)::

import importlib.util import sys

For illustrative purposes.

import tokenize file_path = tokenize.file module_name = tokenize.name

spec = importlib.util.spec_from_file_location(module_name, file_path) module = importlib.util.module_from_spec(spec) spec.loader.exec_module(module)

Optional; only necessary if you want to be able to import the module

by name later.

sys.modules[module_name] = module

Setting up an importer ''''''''''''''''''''''

For deep customizations of import, you typically want to implement an :term:importer. This means managing both the :term:finder and :term:loader side of things. For finders there are two flavours to choose from depending on your needs: a :term:meta path finder or a :term:path entry finder. The former is what you would put on :attr:sys.meta_path while the latter is what you create using a :term:path entry hook on :attr:sys.path_hooks which works with :attr:sys.path entries to potentially create a finder. This example will show you how to register your own importers so that import will use them (for creating an importer for yourself, read the documentation for the appropriate classes defined within this package)::

import importlib.machinery import sys

For illustrative purposes only.

SpamMetaPathFinder = importlib.machinery.PathFinder SpamPathEntryFinder = importlib.machinery.FileFinder loader_details = (importlib.machinery.SourceFileLoader, importlib.machinery.SOURCE_SUFFIXES)

Setting up a meta path finder.

Make sure to put the finder in the proper location in the list in terms of

priority.

sys.meta_path.append(SpamMetaPathFinder)

Setting up a path entry finder.

Make sure to put the path hook in the proper location in the list in terms

of priority.

sys.path_hooks.append(SpamPathEntryFinder.path_hook(loader_details))

Approximating :func:importlib.import_module '''''''''''''''''''''''''''''''''''''''''''''

Import itself is implemented in Python code, making it possible to expose most of the import machinery through importlib. The following helps illustrate the various APIs that importlib exposes by providing an approximate implementation of :func:importlib.import_module (Python 3.4 and newer for the importlib usage, Python 3.6 and newer for other parts of the code). ::

import importlib.util import sys

def import_module(name, package=None): """An approximate implementation of import.""" absolute_name = importlib.util.resolve_name(name, package) try: return sys.modules[absolute_name] except KeyError: pass

  path = None
  if '.' in absolute_name:
      parent_name, _, child_name = absolute_name.rpartition('.')
      parent_module = import_module(parent_name)
      path = parent_module.__spec__.submodule_search_locations
  for finder in sys.meta_path:
      spec = finder.find_spec(absolute_name, path)
      if spec is not None:
          break
  else:
      msg = f'No module named {absolute_name!r}'
      raise ModuleNotFoundError(msg, name=absolute_name)
  module = importlib.util.module_from_spec(spec)
  spec.loader.exec_module(module)
  sys.modules[absolute_name] = module
  if path is not None:
      setattr(parent_module, child_name, module)
  return module

:mod:`!importlib` --- The implementation of :keyword:`!import`

:mod:!importlib --- The implementation of :keyword:!import

Introduction

Functions

:mod:importlib.abc -- Abstract base classes related to import

:mod:importlib.resources -- Resources

:mod:importlib.machinery -- Importers and path hooks

:mod:importlib.util -- Utility code for importers

Examples

For illustrative purposes.

For illustrative purposes.

Optional; only necessary if you want to be able to import the module

by name later.

For illustrative purposes only.

Setting up a meta path finder.

Make sure to put the finder in the proper location in the list in terms of

priority.

Setting up a path entry finder.

Make sure to put the path hook in the proper location in the list in terms

of priority.

:mod:`!importlib` --- The implementation of :keyword:`!import`

:mod:`importlib.abc` -- Abstract base classes related to import

:mod:`importlib.resources` -- Resources

:mod:`importlib.machinery` -- Importers and path hooks

:mod:`importlib.util` -- Utility code for importers