diff --git a/Doc/library/pkgutil.rst b/Doc/library/pkgutil.rst index b17a317244da9e..c791ad5de26d63 100644 --- a/Doc/library/pkgutil.rst +++ b/Doc/library/pkgutil.rst @@ -191,24 +191,48 @@ support. :meth:`get_data ` API. The *package* argument should be the name of a package, in standard module format (``foo.bar``). The *resource* argument should be in the form of a relative - filename, using ``/`` as the path separator. The parent directory name - ``..`` is not allowed, and nor is a rooted name (starting with a ``/``). + filename, using ``/`` as the path separator. The function returns a binary string that is the contents of the specified resource. + This function uses the :term:`loader` method + :func:`~importlib.abc.FileLoader.get_data` + to support modules installed in the filesystem, but also in zip files, + databases, or elsewhere. + For packages located in the filesystem, which have already been imported, this is the rough equivalent of:: d = os.path.dirname(sys.modules[package].__file__) data = open(os.path.join(d, resource), 'rb').read() + Like the :func:`open` function, :func:`!get_data` can follow parent + directories (``../``) and absolute paths (starting with ``/`` or ``C:/``, + for example). + It can open compilation/installation artifacts like ``.py`` and ``.pyc`` + files or files with :func:`reserved filenames `. + To be compatible with non-filesystem loaders, avoid using these features. + + .. warning:: + + This function is intended for trusted input. + It does not verify that *resource* "belongs" to *package*. + + If you use a user-provided *resource* path, consider verifying it. + For example, require an alphanumeric filename with a known extension, or + install and check a list of known resources. + If the package cannot be located or loaded, or it uses a :term:`loader` which does not support :meth:`get_data `, then ``None`` is returned. In particular, the :term:`loader` for :term:`namespace packages ` does not support :meth:`get_data `. + .. seealso:: + + The :mod:`importlib.resources` module provides structured access to + module resources. .. function:: resolve_name(name)