importlib.resources -- パッケージリソースの読み取り、オープン、アクセス

ソースコード: Lib/importlib/resources/__init__.py

Added in version 3.7.

This module leverages Python's import system to provide access to resources within packages.

"Resources" are file-like resources associated with a module or package in Python. The resources may be contained directly in a package, within a subdirectory contained in that package, or adjacent to modules outside a package. Resources may be text or binary. As a result, a package's Python module sources (.py), compilation artifacts (pycache), and installation artifacts (like reserved filenames in directories) are technically de-facto resources of that package. In practice, however, resources are primarily those non-Python artifacts exposed specifically by the package author.

Resources can be opened or read in either binary or text mode.

リソースは大体ディレクトリの中のファイルに似ていますが、これは単なる例え話であることを頭に入れておくことが重要です。例えば、パッケージとそのリソースは zipimport を使って zip ファイルからインポートすることができます。

注釈

このモジュールは、 pkg_resources Basic Resource Access に似た機能を、そのパッケージのパフォーマンスのオーバーヘッドを伴わずに提供します。 これにより、パッケージに含まれるリソースの読み込みがより簡単になり、より安定した一貫した意味付けができるようになります。

このモジュールのスタンドアローンバックポートでは、 importlib.resources の使用 と pkg_resources から importlib.resources への移行 についての詳細情報を提供しています。

Loaders でリソースの読み込みをサポートしたい場合は、 importlib.resources.abc.ResourceReader で指定された get_resource_reader(fullname) メソッドを実装しなければいけません。

class importlib.resources.Anchor

Represents an anchor for resources, either a module object or a module name as a string. Defined as Union[str, ModuleType].

importlib.resources.files(anchor: Anchor | None = None)

Returns a Traversable object representing the resource container (think directory) and its resources (think files). A Traversable may contain other containers (think subdirectories).

anchor is an optional Anchor. If the anchor is a package, resources are resolved from that package. If a module, resources are resolved adjacent to that module (in the same package or the package root). If the anchor is omitted, the caller's module is used.

Added in version 3.9.

バージョン 3.12 で変更: package parameter was renamed to anchor. package was still accepted, but deprecated.

バージョン 3.15 で変更: package parameter was fully removed. anchor can now be a non-package module and if omitted will default to the caller's module. package is no longer accepted since Python 3.15. Consider passing the anchor positionally or using importlib_resources >= 5.10 for a compatible interface on older Pythons.

importlib.resources.as_file(traversable)

Given a Traversable object representing a file or directory, typically from importlib.resources.files(), return a context manager for use in a with statement. The context manager provides a pathlib.Path object.

Exiting the context manager cleans up any temporary file or directory created when the resource was extracted from e.g. a zip file.

Use as_file when the Traversable methods (read_text, etc) are insufficient and an actual file or directory on the file system is required.

Added in version 3.9.

バージョン 3.12 で変更: Added support for traversable representing a directory.

関数 API

A set of simplified, backwards-compatible helpers is available. These allow common operations in a single function call.

For all the following functions:

  • anchor is an Anchor, as in files(). Unlike in files, it may not be omitted.

  • path_names are components of a resource's path name, relative to the anchor. For example, to get the text of resource named info.txt, use:

    importlib.resources.read_text(my_module, "info.txt")

    Like Traversable.joinpath, The individual components should use forward slashes (/) as path separators. For example, the following are equivalent:

    importlib.resources.read_binary(my_module, "pics/painting.png")
importlib.resources.read_binary(my_module, "pics", "painting.png")

    For backward compatibility reasons, functions that read text require an explicit encoding argument if multiple path_names are given. For example, to get the text of info/chapter1.txt, use:

    importlib.resources.read_text(my_module, "info", "chapter1.txt",
                              encoding='utf-8')
importlib.resources.open_binary(anchor, *path_names)

Open the named resource for binary reading.

See the introduction for details on anchor and path_names.

This function returns a BinaryIO object, that is, a binary stream open for reading.

This function is roughly equivalent to:

files(anchor).joinpath(*path_names).open('rb')

バージョン 3.13 で変更: Multiple path_names are accepted.

importlib.resources.open_text(anchor, *path_names, encoding='utf-8', errors='strict')

Open the named resource for text reading. By default, the contents are read as strict UTF-8.

See the introduction for details on anchor and path_names. encoding and errors have the same meaning as in built-in open().

For backward compatibility reasons, the encoding argument must be given explicitly if there are multiple path_names. This limitation is scheduled to be removed in Python 3.15.

This function returns a TextIO object, that is, a text stream open for reading.

This function is roughly equivalent to:

files(anchor).joinpath(*path_names).open('r', encoding=encoding)

バージョン 3.13 で変更: Multiple path_names are accepted. encoding and errors must be given as keyword arguments.

importlib.resources.read_binary(anchor, *path_names)

Read and return the contents of the named resource as bytes.

See the introduction for details on anchor and path_names.

This function is roughly equivalent to:

files(anchor).joinpath(*path_names).read_bytes()

バージョン 3.13 で変更: Multiple path_names are accepted.

importlib.resources.read_text(anchor, *path_names, encoding='utf-8', errors='strict')

Read and return the contents of the named resource as str. By default, the contents are read as strict UTF-8.

See the introduction for details on anchor and path_names. encoding and errors have the same meaning as in built-in open().

For backward compatibility reasons, the encoding argument must be given explicitly if there are multiple path_names. This limitation is scheduled to be removed in Python 3.15.

This function is roughly equivalent to:

files(anchor).joinpath(*path_names).read_text(encoding=encoding)

バージョン 3.13 で変更: Multiple path_names are accepted. encoding and errors must be given as keyword arguments.

importlib.resources.path(anchor, *path_names)

Provides the path to the resource as an actual file system path. This function returns a context manager for use in a with statement. The context manager provides a pathlib.Path object.

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

For example, the stat() method requires an actual file system path; it can be used like this:

with importlib.resources.path(anchor, "resource.txt") as fspath:
    result = fspath.stat()

See the introduction for details on anchor and path_names.

This function is roughly equivalent to:

as_file(files(anchor).joinpath(*path_names))

バージョン 3.13 で変更: Multiple path_names are accepted. encoding and errors must be given as keyword arguments.

importlib.resources.is_resource(anchor, *path_names)

Return True if the named resource exists, otherwise False. This function does not consider directories to be resources.

See the introduction for details on anchor and path_names.

This function is roughly equivalent to:

files(anchor).joinpath(*path_names).is_file()

バージョン 3.13 で変更: Multiple path_names are accepted.

importlib.resources.contents(anchor, *path_names)

Return an iterable over the named items within the package or path. The iterable returns names of resources (e.g. files) and non-resources (e.g. directories) as str. The iterable does not recurse into subdirectories.

See the introduction for details on anchor and path_names.

This function is roughly equivalent to:

for resource in files(anchor).joinpath(*path_names).iterdir():
    yield resource.name

バージョン 3.11 で非推奨: Prefer iterdir() as above, which offers more control over the results and richer functionality.