importlib.resources – Package resource reading, opening and access

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

Nuevo en la versión 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, Python module sources (.py) of a package and compilation artifacts (pycache) 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.

Los recursos son más o menos similares a los archivos dentro de los directorios, aunque es importante tener en cuenta que esto es solo una metáfora. Los recursos y paquetes no deben existir como archivos y directorios físicos en el sistema de archivos: por ejemplo, un paquete y sus recursos se pueden importar desde un archivo zip usando zipimport.

Nota

Este módulo proporciona una funcionalidad similar a pkg_resources Acceso a los recursos básicos sin la sobrecarga de rendimiento de ese paquete. Esto facilita la lectura de los recursos incluidos en los paquetes, con una semántica más estable y consistente.

El soporte independiente de este módulo proporciona más información sobre el uso de importlib.resources y migración de pkg_resources a importlib.resources.

Los loaders que deseen soportar la lectura de recursos deben implementar un método get_resource_reader(fullname) según lo especificado por importlib.resources.abc.ResourceReader.

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.

Nuevo en la versión 3.9.

Distinto en la versión 3.12: package parameter was renamed to anchor. anchor can now be a non-package module and if omitted will default to the caller’s module. package is still accepted for compatibility but will raise a DeprecationWarning. 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.

Nuevo en la versión 3.9.

Distinto en la versión 3.12: Added support for traversable representing a directory.

Functional 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')

Distinto en la versión 3.13: 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)

Distinto en la versión 3.13: 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()

Distinto en la versión 3.13: 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)

Distinto en la versión 3.13: 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))

Distinto en la versión 3.13: 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()

Distinto en la versión 3.13: 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

Obsoleto desde la versión 3.11: Prefer iterdir() as above, which offers more control over the results and richer functionality.