Bug #1694833: fix imp.find_module() docs wrt. packages.

This commit is contained in:
Georg Brandl 2007-08-23 20:50:23 +00:00
parent 891f1d339b
commit 3e0f735ce1
1 changed files with 40 additions and 32 deletions

View File

@ -33,54 +33,62 @@ This module provides an interface to the mechanisms used to implement the
.. function:: find_module(name[, path]) .. function:: find_module(name[, path])
Try to find the module *name* on the search path *path*. If *path* is a list of Try to find the module *name* on the search path *path*. If *path* is a list
directory names, each directory is searched for files with any of the suffixes of directory names, each directory is searched for files with any of the
returned by :func:`get_suffixes` above. Invalid names in the list are silently suffixes returned by :func:`get_suffixes` above. Invalid names in the list
ignored (but all list items must be strings). If *path* is omitted or ``None``, are silently ignored (but all list items must be strings). If *path* is
the list of directory names given by ``sys.path`` is searched, but first it omitted or ``None``, the list of directory names given by ``sys.path`` is
searches a few special places: it tries to find a built-in module with the given searched, but first it searches a few special places: it tries to find a
name (:const:`C_BUILTIN`), then a frozen module (:const:`PY_FROZEN`), and on built-in module with the given name (:const:`C_BUILTIN`), then a frozen
some systems some other places are looked in as well (on the Mac, it looks for a module (:const:`PY_FROZEN`), and on some systems some other places are looked
resource (:const:`PY_RESOURCE`); on Windows, it looks in the registry which may in as well (on the Mac, it looks for a resource (:const:`PY_RESOURCE`); on
point to a specific file). Windows, it looks in the registry which may point to a specific file).
If search is successful, the return value is a triple ``(file, pathname, If search is successful, the return value is a triple ``(file, pathname,
description)`` where *file* is an open file object positioned at the beginning, description)``:
*pathname* is the pathname of the file found, and *description* is a triple as
contained in the list returned by :func:`get_suffixes` describing the kind of
module found. If the module does not live in a file, the returned *file* is
``None``, *filename* is the empty string, and the *description* tuple contains
empty strings for its suffix and mode; the module type is as indicate in
parentheses above. If the search is unsuccessful, :exc:`ImportError` is raised.
Other exceptions indicate problems with the arguments or environment.
This function does not handle hierarchical module names (names containing dots). *file* is an open file object positioned at the beginning, *pathname* is the
In order to find *P*.*M*, that is, submodule *M* of package *P*, use pathname of the file found, and *description* is a triple as contained in the
list returned by :func:`get_suffixes` describing the kind of module found.
If the module does not live in a file, the returned *file* is ``None``,
*pathname* is the empty string, and the *description* tuple contains empty
strings for its suffix and mode; the module type is indicated as given in
parentheses above. If the search is unsuccessful, :exc:`ImportError` is
raised. Other exceptions indicate problems with the arguments or
environment.
If the module is a package, *file* is ``None``, *pathname* is the package
path and the last item in the *description* tuple is :const:`PKG_DIRECTORY`.
This function does not handle hierarchical module names (names containing
dots). In order to find *P*.*M*, that is, submodule *M* of package *P*, use
:func:`find_module` and :func:`load_module` to find and load package *P*, and :func:`find_module` and :func:`load_module` to find and load package *P*, and
then use :func:`find_module` with the *path* argument set to ``P.__path__``. then use :func:`find_module` with the *path* argument set to ``P.__path__``.
When *P* itself has a dotted name, apply this recipe recursively. When *P* itself has a dotted name, apply this recipe recursively.
.. function:: load_module(name, file, filename, description) .. function:: load_module(name, file, pathname, description)
.. index:: builtin: reload .. index:: builtin: reload
Load a module that was previously found by :func:`find_module` (or by an Load a module that was previously found by :func:`find_module` (or by an
otherwise conducted search yielding compatible results). This function does otherwise conducted search yielding compatible results). This function does
more than importing the module: if the module was already imported, it is more than importing the module: if the module was already imported, it is
equivalent to a :func:`reload`! The *name* argument indicates the full module equivalent to a :func:`reload`! The *name* argument indicates the full
name (including the package name, if this is a submodule of a package). The module name (including the package name, if this is a submodule of a
*file* argument is an open file, and *filename* is the corresponding file name; package). The *file* argument is an open file, and *pathname* is the
these can be ``None`` and ``''``, respectively, when the module is not being corresponding file name; these can be ``None`` and ``''``, respectively, when
loaded from a file. The *description* argument is a tuple, as would be returned the module is a package or not being loaded from a file. The *description*
by :func:`get_suffixes`, describing what kind of module must be loaded. argument is a tuple, as would be returned by :func:`get_suffixes`, describing
what kind of module must be loaded.
If the load is successful, the return value is the module object; otherwise, an If the load is successful, the return value is the module object; otherwise,
exception (usually :exc:`ImportError`) is raised. an exception (usually :exc:`ImportError`) is raised.
**Important:** the caller is responsible for closing the *file* argument, if it **Important:** the caller is responsible for closing the *file* argument, if
was not ``None``, even when an exception is raised. This is best done using a it was not ``None``, even when an exception is raised. This is best done
:keyword:`try` ... :keyword:`finally` statement. using a :keyword:`try` ... :keyword:`finally` statement.
.. function:: new_module(name) .. function:: new_module(name)