This module provides an interface to the mechanisms used to implement the import statement. It defines the following constants and functions:
(suffix, mode, type), where suffix is a string to be appended to the module name to form the filename to search for, mode is the mode string to pass to the built-in open() function to open the file (this can be
'r'for text files or
'rb'for binary files), and type is the file type, which has one of the values PY_SOURCE, PY_COMPILED, or C_EXTENSION, described below.
None, the list of directory names given by
sys.pathis searched, but first it searches a few special places: it tries to find a built-in module with the given name (C_BUILTIN), then a frozen module (PY_FROZEN), and on some systems some other places are looked in as well (on the Mac, it looks for a resource (PY_RESOURCE); on 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, description) where
file is an open file object positioned at the beginning,
pathname is the pathname of the
file found, and description is a triple as contained in the list
returned by 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, ImportError is raised. Other
exceptions indicate problems with the arguments or environment.
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 find_module() and
load_module() to find and load package P, and then use
find_module() with the path argument set to
P.__path__. When P itself has a dotted name, apply
this recipe recursively.
|name, file, filename, description)|
'', respectively, when the module is not being loaded from a file. The description argument is a tuple, as would be returned by get_suffixes(), describing what kind of module must be loaded.
If the load is successful, the return value is the module object; otherwise, an exception (usually ImportError) is raised.
Important: the caller is responsible for closing the
file argument, if it was not
None, even when an exception
is raised. This is best done using a try
... finally statement.
Trueif the import lock is currently held, else
False. On platforms without threads, always return
On platforms with threads, a thread executing an import holds an internal lock until the import is complete. This lock blocks other threads from doing an import until the original import completes, which in turn prevents other threads from seeing incomplete module objects constructed by the original thread while in the process of completing its import (and the imports, if any, triggered by that).
The following constants with integer values, defined in this module, are used to indicate the search result of find_module().
The following constant and functions are obsolete; their functionality is available through find_module() or load_module(). They are kept around for backward compatibility:
Noneis returned. (Frozen modules are modules written in Python whose compiled byte-code object is incorporated into a custom-built Python interpreter by Python's freeze utility. See Tools/freeze/ for now.)
1if there is a built-in module called name which can be initialized again. Return
-1if there is a built-in module called name which cannot be initialized again (see init_builtin()). Return
0if there is no built-in module called name.
Trueif there is a frozen module (see init_frozen()) called name, or
Falseif there is no such module.
|name, pathname, file)|
|name, pathname[, file])|
|name, pathname, file)|