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60 lines
2.6 KiB
ReStructuredText
60 lines
2.6 KiB
ReStructuredText
:mod:`pkgutil` --- Package extension utility
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============================================
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.. module:: pkgutil
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:synopsis: Utilities to support extension of packages.
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This module provides functions to manipulate packages:
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.. function:: extend_path(path, name)
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Extend the search path for the modules which comprise a package. Intended use is
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to place the following code in a package's :file:`__init__.py`::
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from pkgutil import extend_path
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__path__ = extend_path(__path__, __name__)
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This will add to the package's ``__path__`` all subdirectories of directories on
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``sys.path`` named after the package. This is useful if one wants to distribute
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different parts of a single logical package as multiple directories.
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It also looks for :file:`\*.pkg` files beginning where ``*`` matches the *name*
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argument. This feature is similar to :file:`\*.pth` files (see the :mod:`site`
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module for more information), except that it doesn't special-case lines starting
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with ``import``. A :file:`\*.pkg` file is trusted at face value: apart from
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checking for duplicates, all entries found in a :file:`\*.pkg` file are added to
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the path, regardless of whether they exist on the filesystem. (This is a
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feature.)
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If the input path is not a list (as is the case for frozen packages) it is
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returned unchanged. The input path is not modified; an extended copy is
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returned. Items are only appended to the copy at the end.
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It is assumed that ``sys.path`` is a sequence. Items of ``sys.path`` that are
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not strings referring to existing directories are ignored. Unicode items on
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``sys.path`` that cause errors when used as filenames may cause this function
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to raise an exception (in line with :func:`os.path.isdir` behavior).
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.. function:: get_data(package, resource)
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Get a resource from a package.
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This is a wrapper for the PEP 302 loader :func:`get_data` API. The package
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argument should be the name of a package, in standard module format
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(foo.bar). The resource argument should be in the form of a relative
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filename, using ``/`` as the path separator. The parent directory name
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``..`` is not allowed, and nor is a rooted name (starting with a ``/``).
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The function returns a binary string that is the contents of the
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specified resource.
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For packages located in the filesystem, which have already been imported,
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this is the rough equivalent of::
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d = os.path.dirname(sys.modules[package].__file__)
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data = open(os.path.join(d, resource), 'rb').read()
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If the package cannot be located or loaded, or it uses a PEP 302 loader
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which does not support :func:`get_data`, then None is returned.
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