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# `importlib` --- The implementation of `import`
3\.1 新版功能.
**Source code:** [Lib/importlib/\_\_init\_\_.py](https://github.com/python/cpython/tree/3.7/Lib/importlib/__init__.py) \[https://github.com/python/cpython/tree/3.7/Lib/importlib/\_\_init\_\_.py\]
- - - - - -
## 概述
The purpose of the [`importlib`](#module-importlib "importlib: The implementation of the import machinery.") package is two-fold. One is to provide the implementation of the [`import`](../reference/simple_stmts.xhtml#import) statement (and thus, by extension, the [`__import__()`](functions.xhtml#__import__ "__import__") function) in Python source code. This provides an implementation of `import` which is portable to any Python interpreter. This also provides an implementation which is easier to comprehend than one implemented in a programming language other than Python.
Two, the components to implement [`import`](../reference/simple_stmts.xhtml#import) are exposed in this package, making it easier for users to create their own custom objects (known generically as an [importer](../glossary.xhtml#term-importer)) to participate in the import process.
參見
[import 語句](../reference/simple_stmts.xhtml#import)The language reference for the [`import`](../reference/simple_stmts.xhtml#import) statement.
[Packages specification](https://www.python.org/doc/essays/packages/) \[https://www.python.org/doc/essays/packages/\]Original specification of packages. Some semantics have changed since the writing of this document (e.g. redirecting based on `None`in [`sys.modules`](sys.xhtml#sys.modules "sys.modules")).
The [`__import__()`](#importlib.__import__ "importlib.__import__") functionThe [`import`](../reference/simple_stmts.xhtml#import) statement is syntactic sugar for this function.
[**PEP 235**](https://www.python.org/dev/peps/pep-0235) \[https://www.python.org/dev/peps/pep-0235\]Import on Case-Insensitive Platforms
[**PEP 263**](https://www.python.org/dev/peps/pep-0263) \[https://www.python.org/dev/peps/pep-0263\]Defining Python Source Code Encodings
[**PEP 302**](https://www.python.org/dev/peps/pep-0302) \[https://www.python.org/dev/peps/pep-0302\]New Import Hooks
[**PEP 328**](https://www.python.org/dev/peps/pep-0328) \[https://www.python.org/dev/peps/pep-0328\]Imports: Multi-Line and Absolute/Relative
[**PEP 366**](https://www.python.org/dev/peps/pep-0366) \[https://www.python.org/dev/peps/pep-0366\]Main module explicit relative imports
[**PEP 420**](https://www.python.org/dev/peps/pep-0420) \[https://www.python.org/dev/peps/pep-0420\]Implicit namespace packages
[**PEP 451**](https://www.python.org/dev/peps/pep-0451) \[https://www.python.org/dev/peps/pep-0451\]A ModuleSpec Type for the Import System
[**PEP 488**](https://www.python.org/dev/peps/pep-0488) \[https://www.python.org/dev/peps/pep-0488\]Elimination of PYO files
[**PEP 489**](https://www.python.org/dev/peps/pep-0489) \[https://www.python.org/dev/peps/pep-0489\]Multi-phase extension module initialization
[**PEP 552**](https://www.python.org/dev/peps/pep-0552) \[https://www.python.org/dev/peps/pep-0552\]Deterministic pycs
[**PEP 3120**](https://www.python.org/dev/peps/pep-3120) \[https://www.python.org/dev/peps/pep-3120\]Using UTF-8 as the Default Source Encoding
[**PEP 3147**](https://www.python.org/dev/peps/pep-3147) \[https://www.python.org/dev/peps/pep-3147\]PYC Repository Directories
## 函數
`importlib.``__import__`(*name*, *globals=None*, *locals=None*, *fromlist=()*, *level=0*)An implementation of the built-in [`__import__()`](functions.xhtml#__import__ "__import__") function.
注解
Programmatic importing of modules should use [`import_module()`](#importlib.import_module "importlib.import_module")instead of this function.
`importlib.``import_module`(*name*, *package=None*)Import a module. The *name* argument specifies what module to import in absolute or relative terms (e.g. either `pkg.mod` or `..mod`). If the name is specified in relative terms, then the *package* argument must be set to the name of the package which is to act as the anchor for resolving the package name (e.g. `import_module('..mod', 'pkg.subpkg')` will import `pkg.mod`).
The [`import_module()`](#importlib.import_module "importlib.import_module") function acts as a simplifying wrapper around [`importlib.__import__()`](#importlib.__import__ "importlib.__import__"). This means all semantics of the function are derived from [`importlib.__import__()`](#importlib.__import__ "importlib.__import__"). The most important difference between these two functions is that [`import_module()`](#importlib.import_module "importlib.import_module") returns the specified package or module (e.g. `pkg.mod`), while [`__import__()`](functions.xhtml#__import__ "__import__")returns the top-level package or module (e.g. `pkg`).
If you are dynamically importing a module that was created since the interpreter began execution (e.g., created a Python source file), you may need to call [`invalidate_caches()`](#importlib.invalidate_caches "importlib.invalidate_caches") in order for the new module to be noticed by the import system.
在 3.3 版更改: Parent packages are automatically imported.
`importlib.``find_loader`(*name*, *path=None*)Find the loader for a module, optionally within the specified *path*. If the module is in [`sys.modules`](sys.xhtml#sys.modules "sys.modules"), then `sys.modules[name].__loader__` is returned (unless the loader would be `None` or is not set, in which case [`ValueError`](exceptions.xhtml#ValueError "ValueError") is raised). Otherwise a search using [`sys.meta_path`](sys.xhtml#sys.meta_path "sys.meta_path")is done. `None` is returned if no loader is found.
A dotted name does not have its parents implicitly imported as that requires loading them and that may not be desired. To properly import a submodule you will need to import all parent packages of the submodule and use the correct argument to *path*.
3\.3 新版功能.
在 3.4 版更改: If `__loader__` is not set, raise [`ValueError`](exceptions.xhtml#ValueError "ValueError"), just like when the attribute is set to `None`.
3\.4 版后已移除: Use [`importlib.util.find_spec()`](#importlib.util.find_spec "importlib.util.find_spec") instead.
`importlib.``invalidate_caches`()Invalidate the internal caches of finders stored at [`sys.meta_path`](sys.xhtml#sys.meta_path "sys.meta_path"). If a finder implements `invalidate_caches()` then it will be called to perform the invalidation. This function should be called if any modules are created/installed while your program is running to guarantee all finders will notice the new module's existence.
3\.3 新版功能.
`importlib.``reload`(*module*)Reload a previously imported *module*. The argument must be a module object, so it must have been successfully imported before. This is useful if you have edited the module source file using an external editor and want to try out the new version without leaving the Python interpreter. The return value is the module object (which can be different if re-importing causes a different object to be placed in [`sys.modules`](sys.xhtml#sys.modules "sys.modules")).
When [`reload()`](#importlib.reload "importlib.reload") is executed:
- Python module's code is recompiled and the module-level code re-executed, defining a new set of objects which are bound to names in the module's dictionary by reusing the [loader](../glossary.xhtml#term-loader) which originally loaded the module. The `init` function of extension modules is not called a second time.
- As with all other objects in Python the old objects are only reclaimed after their reference counts drop to zero.
- The names in the module namespace are updated to point to any new or changed objects.
- Other references to the old objects (such as names external to the module) are not rebound to refer to the new objects and must be updated in each namespace where they occur if that is desired.
There are a number of other caveats:
When a module is reloaded, its dictionary (containing the module's global variables) is retained. Redefinitions of names will override the old definitions, so this is generally not a problem. If the new version of a module does not define a name that was defined by the old version, the old definition remains. This feature can be used to the module's advantage if it maintains a global table or cache of objects --- with a [`try`](../reference/compound_stmts.xhtml#try)statement it can test for the table's presence and skip its initialization if desired:
```
try:
cache
except NameError:
cache = {}
```
It is generally not very useful to reload built-in or dynamically loaded modules. Reloading [`sys`](sys.xhtml#module-sys "sys: Access system-specific parameters and functions."), [`__main__`](__main__.xhtml#module-__main__ "__main__: The environment where the top-level script is run."), [`builtins`](builtins.xhtml#module-builtins "builtins: The module that provides the built-in namespace.") and other key modules is not recommended. In many cases extension modules are not designed to be initialized more than once, and may fail in arbitrary ways when reloaded.
If a module imports objects from another module using [`from`](../reference/simple_stmts.xhtml#from) ... [`import`](../reference/simple_stmts.xhtml#import) ..., calling [`reload()`](#importlib.reload "importlib.reload") for the other module does not redefine the objects imported from it --- one way around this is to re-execute the `from` statement, another is to use `import`and qualified names (*module.name*) instead.
If a module instantiates instances of a class, reloading the module that defines the class does not affect the method definitions of the instances --- they continue to use the old class definition. The same is true for derived classes.
3\.4 新版功能.
在 3.7 版更改: [`ModuleNotFoundError`](exceptions.xhtml#ModuleNotFoundError "ModuleNotFoundError") is raised when the module being reloaded lacks a `ModuleSpec`.
## [`importlib.abc`](#module-importlib.abc "importlib.abc: Abstract base classes related to import") -- Abstract base classes related to import
**Source code:** [Lib/importlib/abc.py](https://github.com/python/cpython/tree/3.7/Lib/importlib/abc.py) \[https://github.com/python/cpython/tree/3.7/Lib/importlib/abc.py\]
- - - - - -
The [`importlib.abc`](#module-importlib.abc "importlib.abc: Abstract base classes related to import") module contains all of the core abstract base classes used by [`import`](../reference/simple_stmts.xhtml#import). Some subclasses of the core abstract base classes are also provided to help in implementing the core ABCs.
ABC hierarchy:
```
object
+-- Finder (deprecated)
| +-- MetaPathFinder
| +-- PathEntryFinder
+-- Loader
+-- ResourceLoader --------+
+-- InspectLoader |
+-- ExecutionLoader --+
+-- FileLoader
+-- SourceLoader
```
*class* `importlib.abc.``Finder`An abstract base class representing a [finder](../glossary.xhtml#term-finder).
3\.3 版后已移除: Use [`MetaPathFinder`](#importlib.abc.MetaPathFinder "importlib.abc.MetaPathFinder") or [`PathEntryFinder`](#importlib.abc.PathEntryFinder "importlib.abc.PathEntryFinder") instead.
*abstractmethod* `find_module`(*fullname*, *path=None*)An abstract method for finding a [loader](../glossary.xhtml#term-loader) for the specified module. Originally specified in [**PEP 302**](https://www.python.org/dev/peps/pep-0302) \[https://www.python.org/dev/peps/pep-0302\], this method was meant for use in [`sys.meta_path`](sys.xhtml#sys.meta_path "sys.meta_path") and in the path-based import subsystem.
在 3.4 版更改: Returns `None` when called instead of raising [`NotImplementedError`](exceptions.xhtml#NotImplementedError "NotImplementedError").
*class* `importlib.abc.``MetaPathFinder`An abstract base class representing a [meta path finder](../glossary.xhtml#term-meta-path-finder). For compatibility, this is a subclass of [`Finder`](#importlib.abc.Finder "importlib.abc.Finder").
3\.3 新版功能.
`find_spec`(*fullname*, *path*, *target=None*)An abstract method for finding a [spec](../glossary.xhtml#term-module-spec) for the specified module. If this is a top-level import, *path* will be `None`. Otherwise, this is a search for a subpackage or module and *path* will be the value of [`__path__`](../reference/import.xhtml#__path__ "__path__") from the parent package. If a spec cannot be found, `None` is returned. When passed in, `target` is a module object that the finder may use to make a more educated guess about what spec to return.
3\.4 新版功能.
`find_module`(*fullname*, *path*)A legacy method for finding a [loader](../glossary.xhtml#term-loader) for the specified module. If this is a top-level import, *path* will be `None`. Otherwise, this is a search for a subpackage or module and *path*will be the value of [`__path__`](../reference/import.xhtml#__path__ "__path__") from the parent package. If a loader cannot be found, `None` is returned.
If [`find_spec()`](#importlib.abc.MetaPathFinder.find_spec "importlib.abc.MetaPathFinder.find_spec") is defined, backwards-compatible functionality is provided.
在 3.4 版更改: Returns `None` when called instead of raising [`NotImplementedError`](exceptions.xhtml#NotImplementedError "NotImplementedError"). Can use [`find_spec()`](#importlib.abc.MetaPathFinder.find_spec "importlib.abc.MetaPathFinder.find_spec") to provide functionality.
3\.4 版后已移除: Use [`find_spec()`](#importlib.abc.MetaPathFinder.find_spec "importlib.abc.MetaPathFinder.find_spec") instead.
`invalidate_caches`()An optional method which, when called, should invalidate any internal cache used by the finder. Used by [`importlib.invalidate_caches()`](#importlib.invalidate_caches "importlib.invalidate_caches")when invalidating the caches of all finders on [`sys.meta_path`](sys.xhtml#sys.meta_path "sys.meta_path").
在 3.4 版更改: Returns `None` when called instead of `NotImplemented`.
*class* `importlib.abc.``PathEntryFinder`An abstract base class representing a [path entry finder](../glossary.xhtml#term-path-entry-finder). Though it bears some similarities to [`MetaPathFinder`](#importlib.abc.MetaPathFinder "importlib.abc.MetaPathFinder"), `PathEntryFinder`is meant for use only within the path-based import subsystem provided by `PathFinder`. This ABC is a subclass of [`Finder`](#importlib.abc.Finder "importlib.abc.Finder") for compatibility reasons only.
3\.3 新版功能.
`find_spec`(*fullname*, *target=None*)An abstract method for finding a [spec](../glossary.xhtml#term-module-spec) for the specified module. The finder will search for the module only within the [path entry](../glossary.xhtml#term-path-entry) to which it is assigned. If a spec cannot be found, `None` is returned. When passed in, `target`is a module object that the finder may use to make a more educated guess about what spec to return.
3\.4 新版功能.
`find_loader`(*fullname*)A legacy method for finding a [loader](../glossary.xhtml#term-loader) for the specified module. Returns a 2-tuple of `(loader, portion)` where `portion`is a sequence of file system locations contributing to part of a namespace package. The loader may be `None` while specifying `portion` to signify the contribution of the file system locations to a namespace package. An empty list can be used for `portion` to signify the loader is not part of a namespace package. If `loader` is `None` and `portion` is the empty list then no loader or location for a namespace package were found (i.e. failure to find anything for the module).
If [`find_spec()`](#importlib.abc.PathEntryFinder.find_spec "importlib.abc.PathEntryFinder.find_spec") is defined then backwards-compatible functionality is provided.
在 3.4 版更改: Returns `(None, [])` instead of raising [`NotImplementedError`](exceptions.xhtml#NotImplementedError "NotImplementedError"). Uses [`find_spec()`](#importlib.abc.PathEntryFinder.find_spec "importlib.abc.PathEntryFinder.find_spec") when available to provide functionality.
3\.4 版后已移除: Use [`find_spec()`](#importlib.abc.PathEntryFinder.find_spec "importlib.abc.PathEntryFinder.find_spec") instead.
`find_module`(*fullname*)A concrete implementation of [`Finder.find_module()`](#importlib.abc.Finder.find_module "importlib.abc.Finder.find_module") which is equivalent to `self.find_loader(fullname)[0]`.
3\.4 版后已移除: Use [`find_spec()`](#importlib.abc.PathEntryFinder.find_spec "importlib.abc.PathEntryFinder.find_spec") instead.
`invalidate_caches`()An optional method which, when called, should invalidate any internal cache used by the finder. Used by `PathFinder.invalidate_caches()`when invalidating the caches of all cached finders.
*class* `importlib.abc.``Loader`An abstract base class for a [loader](../glossary.xhtml#term-loader). See [**PEP 302**](https://www.python.org/dev/peps/pep-0302) \[https://www.python.org/dev/peps/pep-0302\] for the exact definition for a loader.
Loaders that wish to support resource reading should implement a `get_resource_reader(fullname)` method as specified by [`importlib.abc.ResourceReader`](#importlib.abc.ResourceReader "importlib.abc.ResourceReader").
在 3.7 版更改: Introduced the optional `get_resource_reader()` method.
`create_module`(*spec*)A method that returns the module object to use when importing a module. This method may return `None`, indicating that default module creation semantics should take place.
3\.4 新版功能.
在 3.5 版更改: Starting in Python 3.6, this method will not be optional when [`exec_module()`](#importlib.abc.Loader.exec_module "importlib.abc.Loader.exec_module") is defined.
`exec_module`(*module*)An abstract method that executes the module in its own namespace when a module is imported or reloaded. The module should already be initialized when `exec_module()` is called. When this method exists, [`create_module()`](#importlib.abc.Loader.create_module "importlib.abc.Loader.create_module") must be defined.
3\.4 新版功能.
在 3.6 版更改: [`create_module()`](#importlib.abc.Loader.create_module "importlib.abc.Loader.create_module") must also be defined.
`load_module`(*fullname*)A legacy method for loading a module. If the module cannot be loaded, [`ImportError`](exceptions.xhtml#ImportError "ImportError") is raised, otherwise the loaded module is returned.
If the requested module already exists in [`sys.modules`](sys.xhtml#sys.modules "sys.modules"), that module should be used and reloaded. Otherwise the loader should create a new module and insert it into [`sys.modules`](sys.xhtml#sys.modules "sys.modules") before any loading begins, to prevent recursion from the import. If the loader inserted a module and the load fails, it must be removed by the loader from [`sys.modules`](sys.xhtml#sys.modules "sys.modules"); modules already in [`sys.modules`](sys.xhtml#sys.modules "sys.modules") before the loader began execution should be left alone (see [`importlib.util.module_for_loader()`](#importlib.util.module_for_loader "importlib.util.module_for_loader")).
The loader should set several attributes on the module. (Note that some of these attributes can change when a module is reloaded):
- [`__name__`](../reference/import.xhtml#__name__ "__name__")The name of the module.
- [`__file__`](../reference/import.xhtml#__file__ "__file__")The path to where the module data is stored (not set for built-in modules).
- [`__cached__`](../reference/import.xhtml#__cached__ "__cached__")The path to where a compiled version of the module is/should be stored (not set when the attribute would be inappropriate).
- [`__path__`](../reference/import.xhtml#__path__ "__path__")A list of strings specifying the search path within a package. This attribute is not set on modules.
- [`__package__`](../reference/import.xhtml#__package__ "__package__")The parent package for the module/package. If the module is top-level then it has a value of the empty string. The [`importlib.util.module_for_loader()`](#importlib.util.module_for_loader "importlib.util.module_for_loader") decorator can handle the details for [`__package__`](../reference/import.xhtml#__package__ "__package__").
- [`__loader__`](../reference/import.xhtml#__loader__ "__loader__")The loader used to load the module. The [`importlib.util.module_for_loader()`](#importlib.util.module_for_loader "importlib.util.module_for_loader") decorator can handle the details for [`__package__`](../reference/import.xhtml#__package__ "__package__").
When [`exec_module()`](#importlib.abc.Loader.exec_module "importlib.abc.Loader.exec_module") is available then backwards-compatible functionality is provided.
在 3.4 版更改: Raise [`ImportError`](exceptions.xhtml#ImportError "ImportError") when called instead of [`NotImplementedError`](exceptions.xhtml#NotImplementedError "NotImplementedError"). Functionality provided when [`exec_module()`](#importlib.abc.Loader.exec_module "importlib.abc.Loader.exec_module") is available.
3\.4 版后已移除: The recommended API for loading a module is [`exec_module()`](#importlib.abc.Loader.exec_module "importlib.abc.Loader.exec_module")(and [`create_module()`](#importlib.abc.Loader.create_module "importlib.abc.Loader.create_module")). Loaders should implement it instead of load\_module(). The import machinery takes care of all the other responsibilities of load\_module() when exec\_module() is implemented.
`module_repr`(*module*)A legacy method which when implemented calculates and returns the given module's repr, as a string. The module type's default repr() will use the result of this method as appropriate.
3\.3 新版功能.
在 3.4 版更改: Made optional instead of an abstractmethod.
3\.4 版后已移除: The import machinery now takes care of this automatically.
*class* `importlib.abc.``ResourceReader`An [abstract base class](../glossary.xhtml#term-abstract-base-class) to provide the ability to read *resources*.
From the perspective of this ABC, a *resource* is a binary artifact that is shipped within a package. Typically this is something like a data file that lives next to the `__init__.py`file of the package. The purpose of this class is to help abstract out the accessing of such data files so that it does not matter if the package and its data file(s) are stored in a e.g. zip file versus on the file system.
For any of methods of this class, a *resource* argument is expected to be a [path-like object](../glossary.xhtml#term-path-like-object) which represents conceptually just a file name. This means that no subdirectory paths should be included in the *resource* argument. This is because the location of the package the reader is for, acts as the "directory". Hence the metaphor for directories and file names is packages and resources, respectively. This is also why instances of this class are expected to directly correlate to a specific package (instead of potentially representing multiple packages or a module).
Loaders that wish to support resource reading are expected to provide a method called `get_resource_loader(fullname)` which returns an object implementing this ABC's interface. If the module specified by fullname is not a package, this method should return [`None`](constants.xhtml#None "None"). An object compatible with this ABC should only be returned when the specified module is a package.
3\.7 新版功能.
*abstractmethod* `open_resource`(*resource*)Returns an opened, [file-like object](../glossary.xhtml#term-file-like-object) for binary reading of the *resource*.
If the resource cannot be found, [`FileNotFoundError`](exceptions.xhtml#FileNotFoundError "FileNotFoundError") is raised.
*abstractmethod* `resource_path`(*resource*)Returns the file system path to the *resource*.
If the resource does not concretely exist on the file system, raise [`FileNotFoundError`](exceptions.xhtml#FileNotFoundError "FileNotFoundError").
*abstractmethod* `is_resource`(*name*)Returns `True` if the named *name* is considered a resource. [`FileNotFoundError`](exceptions.xhtml#FileNotFoundError "FileNotFoundError") is raised if *name* does not exist.
*abstractmethod* `contents`()Returns an [iterable](../glossary.xhtml#term-iterable) of strings over the contents of the package. Do note that it is not required that all names returned by the iterator be actual resources, e.g. it is acceptable to return names for which [`is_resource()`](#importlib.abc.ResourceReader.is_resource "importlib.abc.ResourceReader.is_resource") would be false.
Allowing non-resource names to be returned is to allow for situations where how a package and its resources are stored are known a priori and the non-resource names would be useful. For instance, returning subdirectory names is allowed so that when it is known that the package and resources are stored on the file system then those subdirectory names can be used directly.
The abstract method returns an iterable of no items.
*class* `importlib.abc.``ResourceLoader`An abstract base class for a [loader](../glossary.xhtml#term-loader) which implements the optional [**PEP 302**](https://www.python.org/dev/peps/pep-0302) \[https://www.python.org/dev/peps/pep-0302\] protocol for loading arbitrary resources from the storage back-end.
3\.7 版后已移除: This ABC is deprecated in favour of supporting resource loading through [`importlib.abc.ResourceReader`](#importlib.abc.ResourceReader "importlib.abc.ResourceReader").
*abstractmethod* `get_data`(*path*)An abstract method to return the bytes for the data located at *path*. Loaders that have a file-like storage back-end that allows storing arbitrary data can implement this abstract method to give direct access to the data stored. [`OSError`](exceptions.xhtml#OSError "OSError") is to be raised if the *path* cannot be found. The *path* is expected to be constructed using a module's [`__file__`](../reference/import.xhtml#__file__ "__file__") attribute or an item from a package's [`__path__`](../reference/import.xhtml#__path__ "__path__").
在 3.4 版更改: Raises [`OSError`](exceptions.xhtml#OSError "OSError") instead of [`NotImplementedError`](exceptions.xhtml#NotImplementedError "NotImplementedError").
*class* `importlib.abc.``InspectLoader`An abstract base class for a [loader](../glossary.xhtml#term-loader) which implements the optional [**PEP 302**](https://www.python.org/dev/peps/pep-0302) \[https://www.python.org/dev/peps/pep-0302\] protocol for loaders that inspect modules.
`get_code`(*fullname*)Return the code object for a module, or `None` if the module does not have a code object (as would be the case, for example, for a built-in module). Raise an [`ImportError`](exceptions.xhtml#ImportError "ImportError") if loader cannot find the requested module.
注解
While the method has a default implementation, it is suggested that it be overridden if possible for performance.
在 3.4 版更改: No longer abstract and a concrete implementation is provided.
*abstractmethod* `get_source`(*fullname*)An abstract method to return the source of a module. It is returned as a text string using [universal newlines](../glossary.xhtml#term-universal-newlines), translating all recognized line separators into `'\n'` characters. Returns `None`if no source is available (e.g. a built-in module). Raises [`ImportError`](exceptions.xhtml#ImportError "ImportError") if the loader cannot find the module specified.
在 3.4 版更改: Raises [`ImportError`](exceptions.xhtml#ImportError "ImportError") instead of [`NotImplementedError`](exceptions.xhtml#NotImplementedError "NotImplementedError").
`is_package`(*fullname*)An abstract method to return a true value if the module is a package, a false value otherwise. [`ImportError`](exceptions.xhtml#ImportError "ImportError") is raised if the [loader](../glossary.xhtml#term-loader) cannot find the module.
在 3.4 版更改: Raises [`ImportError`](exceptions.xhtml#ImportError "ImportError") instead of [`NotImplementedError`](exceptions.xhtml#NotImplementedError "NotImplementedError").
*static* `source_to_code`(*data*, *path='<string>'*)Create a code object from Python source.
The *data* argument can be whatever the [`compile()`](functions.xhtml#compile "compile") function supports (i.e. string or bytes). The *path* argument should be the "path" to where the source code originated from, which can be an abstract concept (e.g. location in a zip file).
With the subsequent code object one can execute it in a module by running `exec(code, module.__dict__)`.
3\.4 新版功能.
在 3.5 版更改: Made the method static.
`exec_module`(*module*)Implementation of [`Loader.exec_module()`](#importlib.abc.Loader.exec_module "importlib.abc.Loader.exec_module").
3\.4 新版功能.
`load_module`(*fullname*)Implementation of [`Loader.load_module()`](#importlib.abc.Loader.load_module "importlib.abc.Loader.load_module").
3\.4 版后已移除: use [`exec_module()`](#importlib.abc.InspectLoader.exec_module "importlib.abc.InspectLoader.exec_module") instead.
*class* `importlib.abc.``ExecutionLoader`An abstract base class which inherits from [`InspectLoader`](#importlib.abc.InspectLoader "importlib.abc.InspectLoader") that, when implemented, helps a module to be executed as a script. The ABC represents an optional [**PEP 302**](https://www.python.org/dev/peps/pep-0302) \[https://www.python.org/dev/peps/pep-0302\] protocol.
*abstractmethod* `get_filename`(*fullname*)An abstract method that is to return the value of [`__file__`](../reference/import.xhtml#__file__ "__file__") for the specified module. If no path is available, [`ImportError`](exceptions.xhtml#ImportError "ImportError") is raised.
If source code is available, then the method should return the path to the source file, regardless of whether a bytecode was used to load the module.
在 3.4 版更改: Raises [`ImportError`](exceptions.xhtml#ImportError "ImportError") instead of [`NotImplementedError`](exceptions.xhtml#NotImplementedError "NotImplementedError").
*class* `importlib.abc.``FileLoader`(*fullname*, *path*)An abstract base class which inherits from [`ResourceLoader`](#importlib.abc.ResourceLoader "importlib.abc.ResourceLoader") and [`ExecutionLoader`](#importlib.abc.ExecutionLoader "importlib.abc.ExecutionLoader"), providing concrete implementations of [`ResourceLoader.get_data()`](#importlib.abc.ResourceLoader.get_data "importlib.abc.ResourceLoader.get_data") and [`ExecutionLoader.get_filename()`](#importlib.abc.ExecutionLoader.get_filename "importlib.abc.ExecutionLoader.get_filename").
The *fullname* argument is a fully resolved name of the module the loader is to handle. The *path* argument is the path to the file for the module.
3\.3 新版功能.
`name`The name of the module the loader can handle.
`path`Path to the file of the module.
`load_module`(*fullname*)Calls super's `load_module()`.
3\.4 版后已移除: Use [`Loader.exec_module()`](#importlib.abc.Loader.exec_module "importlib.abc.Loader.exec_module") instead.
*abstractmethod* `get_filename`(*fullname*)Returns [`path`](#importlib.abc.FileLoader.path "importlib.abc.FileLoader.path").
*abstractmethod* `get_data`(*path*)Reads *path* as a binary file and returns the bytes from it.
*class* `importlib.abc.``SourceLoader`An abstract base class for implementing source (and optionally bytecode) file loading. The class inherits from both [`ResourceLoader`](#importlib.abc.ResourceLoader "importlib.abc.ResourceLoader") and [`ExecutionLoader`](#importlib.abc.ExecutionLoader "importlib.abc.ExecutionLoader"), requiring the implementation of:
- [`ResourceLoader.get_data()`](#importlib.abc.ResourceLoader.get_data "importlib.abc.ResourceLoader.get_data")
- [`ExecutionLoader.get_filename()`](#importlib.abc.ExecutionLoader.get_filename "importlib.abc.ExecutionLoader.get_filename")Should only return the path to the source file; sourceless loading is not supported.
The abstract methods defined by this class are to add optional bytecode file support. Not implementing these optional methods (or causing them to raise [`NotImplementedError`](exceptions.xhtml#NotImplementedError "NotImplementedError")) causes the loader to only work with source code. Implementing the methods allows the loader to work with source *and* bytecode files; it does not allow for *sourceless*loading where only bytecode is provided. Bytecode files are an optimization to speed up loading by removing the parsing step of Python's compiler, and so no bytecode-specific API is exposed.
`path_stats`(*path*)Optional abstract method which returns a [`dict`](stdtypes.xhtml#dict "dict") containing metadata about the specified path. Supported dictionary keys are:
- `'mtime'` (mandatory): an integer or floating-point number representing the modification time of the source code;
- `'size'` (optional): the size in bytes of the source code.
Any other keys in the dictionary are ignored, to allow for future extensions. If the path cannot be handled, [`OSError`](exceptions.xhtml#OSError "OSError") is raised.
3\.3 新版功能.
在 3.4 版更改: Raise [`OSError`](exceptions.xhtml#OSError "OSError") instead of [`NotImplementedError`](exceptions.xhtml#NotImplementedError "NotImplementedError").
`path_mtime`(*path*)Optional abstract method which returns the modification time for the specified path.
3\.3 版后已移除: This method is deprecated in favour of [`path_stats()`](#importlib.abc.SourceLoader.path_stats "importlib.abc.SourceLoader.path_stats"). You don't have to implement it, but it is still available for compatibility purposes. Raise [`OSError`](exceptions.xhtml#OSError "OSError") if the path cannot be handled.
在 3.4 版更改: Raise [`OSError`](exceptions.xhtml#OSError "OSError") instead of [`NotImplementedError`](exceptions.xhtml#NotImplementedError "NotImplementedError").
`set_data`(*path*, *data*)Optional abstract method which writes the specified bytes to a file path. Any intermediate directories which do not exist are to be created automatically.
When writing to the path fails because the path is read-only ([`errno.EACCES`](errno.xhtml#errno.EACCES "errno.EACCES")/[`PermissionError`](exceptions.xhtml#PermissionError "PermissionError")), do not propagate the exception.
在 3.4 版更改: No longer raises [`NotImplementedError`](exceptions.xhtml#NotImplementedError "NotImplementedError") when called.
`get_code`(*fullname*)Concrete implementation of [`InspectLoader.get_code()`](#importlib.abc.InspectLoader.get_code "importlib.abc.InspectLoader.get_code").
`exec_module`(*module*)Concrete implementation of [`Loader.exec_module()`](#importlib.abc.Loader.exec_module "importlib.abc.Loader.exec_module").
3\.4 新版功能.
`load_module`(*fullname*)Concrete implementation of [`Loader.load_module()`](#importlib.abc.Loader.load_module "importlib.abc.Loader.load_module").
3\.4 版后已移除: Use [`exec_module()`](#importlib.abc.SourceLoader.exec_module "importlib.abc.SourceLoader.exec_module") instead.
`get_source`(*fullname*)Concrete implementation of [`InspectLoader.get_source()`](#importlib.abc.InspectLoader.get_source "importlib.abc.InspectLoader.get_source").
`is_package`(*fullname*)Concrete implementation of [`InspectLoader.is_package()`](#importlib.abc.InspectLoader.is_package "importlib.abc.InspectLoader.is_package"). A module is determined to be a package if its file path (as provided by [`ExecutionLoader.get_filename()`](#importlib.abc.ExecutionLoader.get_filename "importlib.abc.ExecutionLoader.get_filename")) is a file named `__init__` when the file extension is removed **and** the module name itself does not end in `__init__`.
## [`importlib.resources`](#module-importlib.resources "importlib.resources: Package resource reading, opening, and access") -- Resources
**Source code:** [Lib/importlib/resources.py](https://github.com/python/cpython/tree/3.7/Lib/importlib/resources.py) \[https://github.com/python/cpython/tree/3.7/Lib/importlib/resources.py\]
- - - - - -
3\.7 新版功能.
This module leverages Python's import system to provide access to *resources*within *packages*. If you can import a package, you can access resources within that package. Resources can be opened or read, in either binary or text mode.
Resources are roughly akin to files inside directories, though it's important to keep in mind that this is just a metaphor. Resources and packages **do not** have to exist as physical files and directories on the file system.
注解
This module provides functionality similar to [pkg\_resources](https://setuptools.readthedocs.io/en/latest/pkg_resources.html) \[https://setuptools.readthedocs.io/en/latest/pkg\_resources.html\] [Basic Resource Access](http://setuptools.readthedocs.io/en/latest/pkg_resources.html#basic-resource-access) \[http://setuptools.readthedocs.io/en/latest/pkg\_resources.html#basic-resource-access\]without the performance overhead of that package. This makes reading resources included in packages easier, with more stable and consistent semantics.
The standalone backport of this module provides more information on [using importlib.resources](http://importlib-resources.readthedocs.io/en/latest/using.html) \[http://importlib-resources.readthedocs.io/en/latest/using.html\] and [migrating from pkg\_resources to importlib.resources](http://importlib-resources.readthedocs.io/en/latest/migration.html) \[http://importlib-resources.readthedocs.io/en/latest/migration.html\].
Loaders that wish to support resource reading should implement a `get_resource_reader(fullname)` method as specified by [`importlib.abc.ResourceReader`](#importlib.abc.ResourceReader "importlib.abc.ResourceReader").
The following types are defined.
`importlib.resources.``Package`The `Package` type is defined as `Union[str, ModuleType]`. This means that where the function describes accepting a `Package`, you can pass in either a string or a module. Module objects must have a resolvable `__spec__.submodule_search_locations` that is not `None`.
`importlib.resources.``Resource`This type describes the resource names passed into the various functions in this package. This is defined as `Union[str, os.PathLike]`.
The following functions are available.
`importlib.resources.``open_binary`(*package*, *resource*)Open for binary reading the *resource* within *package*.
*package* is either a name or a module object which conforms to the `Package` requirements. *resource* is the name of the resource to open within *package*; it may not contain path separators and it may not have sub-resources (i.e. it cannot be a directory). This function returns a `typing.BinaryIO` instance, a binary I/O stream open for reading.
`importlib.resources.``open_text`(*package*, *resource*, *encoding='utf-8'*, *errors='strict'*)Open for text reading the *resource* within *package*. By default, the resource is opened for reading as UTF-8.
*package* is either a name or a module object which conforms to the `Package` requirements. *resource* is the name of the resource to open within *package*; it may not contain path separators and it may not have sub-resources (i.e. it cannot be a directory). *encoding* and *errors*have the same meaning as with built-in [`open()`](functions.xhtml#open "open").
This function returns a `typing.TextIO` instance, a text I/O stream open for reading.
`importlib.resources.``read_binary`(*package*, *resource*)Read and return the contents of the *resource* within *package* as `bytes`.
*package* is either a name or a module object which conforms to the `Package` requirements. *resource* is the name of the resource to open within *package*; it may not contain path separators and it may not have sub-resources (i.e. it cannot be a directory). This function returns the contents of the resource as [`bytes`](stdtypes.xhtml#bytes "bytes").
`importlib.resources.``read_text`(*package*, *resource*, *encoding='utf-8'*, *errors='strict'*)Read and return the contents of *resource* within *package* as a `str`. By default, the contents are read as strict UTF-8.
*package* is either a name or a module object which conforms to the `Package` requirements. *resource* is the name of the resource to open within *package*; it may not contain path separators and it may not have sub-resources (i.e. it cannot be a directory). *encoding* and *errors*have the same meaning as with built-in [`open()`](functions.xhtml#open "open"). This function returns the contents of the resource as [`str`](stdtypes.xhtml#str "str").
`importlib.resources.``path`(*package*, *resource*)Return the path to the *resource* as an actual file system path. This function returns a context manager for use in a [`with`](../reference/compound_stmts.xhtml#with) statement. The context manager provides a [`pathlib.Path`](pathlib.xhtml#pathlib.Path "pathlib.Path") object.
Exiting the context manager cleans up any temporary file created when the resource needs to be extracted from e.g. a zip file.
*package* is either a name or a module object which conforms to the `Package` requirements. *resource* is the name of the resource to open within *package*; it may not contain path separators and it may not have sub-resources (i.e. it cannot be a directory).
`importlib.resources.``is_resource`(*package*, *name*)Return `True` if there is a resource named *name* in the package, otherwise `False`. Remember that directories are *not* resources! *package* is either a name or a module object which conforms to the `Package` requirements.
`importlib.resources.``contents`(*package*)Return an iterable over the named items within the package. The iterable returns [`str`](stdtypes.xhtml#str "str") resources (e.g. files) and non-resources (e.g. directories). The iterable does not recurse into subdirectories.
*package* is either a name or a module object which conforms to the `Package` requirements.
## [`importlib.machinery`](#module-importlib.machinery "importlib.machinery: Importers and path hooks") -- Importers and path hooks
**Source code:** [Lib/importlib/machinery.py](https://github.com/python/cpython/tree/3.7/Lib/importlib/machinery.py) \[https://github.com/python/cpython/tree/3.7/Lib/importlib/machinery.py\]
- - - - - -
This module contains the various objects that help [`import`](../reference/simple_stmts.xhtml#import)find and load modules.
`importlib.machinery.``SOURCE_SUFFIXES`A list of strings representing the recognized file suffixes for source modules.
3\.3 新版功能.
`importlib.machinery.``DEBUG_BYTECODE_SUFFIXES`A list of strings representing the file suffixes for non-optimized bytecode modules.
3\.3 新版功能.
3\.5 版后已移除: Use [`BYTECODE_SUFFIXES`](#importlib.machinery.BYTECODE_SUFFIXES "importlib.machinery.BYTECODE_SUFFIXES") instead.
`importlib.machinery.``OPTIMIZED_BYTECODE_SUFFIXES`A list of strings representing the file suffixes for optimized bytecode modules.
3\.3 新版功能.
3\.5 版后已移除: Use [`BYTECODE_SUFFIXES`](#importlib.machinery.BYTECODE_SUFFIXES "importlib.machinery.BYTECODE_SUFFIXES") instead.
`importlib.machinery.``BYTECODE_SUFFIXES`A list of strings representing the recognized file suffixes for bytecode modules (including the leading dot).
3\.3 新版功能.
在 3.5 版更改: The value is no longer dependent on `__debug__`.
`importlib.machinery.``EXTENSION_SUFFIXES`A list of strings representing the recognized file suffixes for extension modules.
3\.3 新版功能.
`importlib.machinery.``all_suffixes`()Returns a combined list of strings representing all file suffixes for modules recognized by the standard import machinery. This is a helper for code which simply needs to know if a filesystem path potentially refers to a module without needing any details on the kind of module (for example, [`inspect.getmodulename()`](inspect.xhtml#inspect.getmodulename "inspect.getmodulename")).
3\.3 新版功能.
*class* `importlib.machinery.``BuiltinImporter`An [importer](../glossary.xhtml#term-importer) for built-in modules. All known built-in modules are listed in [`sys.builtin_module_names`](sys.xhtml#sys.builtin_module_names "sys.builtin_module_names"). This class implements the [`importlib.abc.MetaPathFinder`](#importlib.abc.MetaPathFinder "importlib.abc.MetaPathFinder") and [`importlib.abc.InspectLoader`](#importlib.abc.InspectLoader "importlib.abc.InspectLoader") ABCs.
Only class methods are defined by this class to alleviate the need for instantiation.
在 3.5 版更改: As part of [**PEP 489**](https://www.python.org/dev/peps/pep-0489) \[https://www.python.org/dev/peps/pep-0489\], the builtin importer now implements `Loader.create_module()` and `Loader.exec_module()`
*class* `importlib.machinery.``FrozenImporter`An [importer](../glossary.xhtml#term-importer) for frozen modules. This class implements the [`importlib.abc.MetaPathFinder`](#importlib.abc.MetaPathFinder "importlib.abc.MetaPathFinder") and [`importlib.abc.InspectLoader`](#importlib.abc.InspectLoader "importlib.abc.InspectLoader") ABCs.
Only class methods are defined by this class to alleviate the need for instantiation.
*class* `importlib.machinery.``WindowsRegistryFinder`[Finder](../glossary.xhtml#term-finder) for modules declared in the Windows registry. This class implements the [`importlib.abc.MetaPathFinder`](#importlib.abc.MetaPathFinder "importlib.abc.MetaPathFinder") ABC.
Only class methods are defined by this class to alleviate the need for instantiation.
3\.3 新版功能.
3\.6 版后已移除: Use [`site`](site.xhtml#module-site "site: Module responsible for site-specific configuration.") configuration instead. Future versions of Python may not enable this finder by default.
*class* `importlib.machinery.``PathFinder`A [Finder](../glossary.xhtml#term-finder) for [`sys.path`](sys.xhtml#sys.path "sys.path") and package `__path__` attributes. This class implements the [`importlib.abc.MetaPathFinder`](#importlib.abc.MetaPathFinder "importlib.abc.MetaPathFinder") ABC.
Only class methods are defined by this class to alleviate the need for instantiation.
*classmethod* `find_spec`(*fullname*, *path=None*, *target=None*)Class method that attempts to find a [spec](../glossary.xhtml#term-module-spec)for the module specified by *fullname* on [`sys.path`](sys.xhtml#sys.path "sys.path") or, if defined, on *path*. For each path entry that is searched, [`sys.path_importer_cache`](sys.xhtml#sys.path_importer_cache "sys.path_importer_cache") is checked. If a non-false object is found then it is used as the [path entry finder](../glossary.xhtml#term-path-entry-finder) to look for the module being searched for. If no entry is found in [`sys.path_importer_cache`](sys.xhtml#sys.path_importer_cache "sys.path_importer_cache"), then [`sys.path_hooks`](sys.xhtml#sys.path_hooks "sys.path_hooks") is searched for a finder for the path entry and, if found, is stored in [`sys.path_importer_cache`](sys.xhtml#sys.path_importer_cache "sys.path_importer_cache") along with being queried about the module. If no finder is ever found then `None` is both stored in the cache and returned.
3\.4 新版功能.
在 3.5 版更改: If the current working directory -- represented by an empty string -- is no longer valid then `None` is returned but no value is cached in [`sys.path_importer_cache`](sys.xhtml#sys.path_importer_cache "sys.path_importer_cache").
*classmethod* `find_module`(*fullname*, *path=None*)A legacy wrapper around [`find_spec()`](#importlib.machinery.PathFinder.find_spec "importlib.machinery.PathFinder.find_spec").
3\.4 版后已移除: Use [`find_spec()`](#importlib.machinery.PathFinder.find_spec "importlib.machinery.PathFinder.find_spec") instead.
*classmethod* `invalidate_caches`()Calls [`importlib.abc.PathEntryFinder.invalidate_caches()`](#importlib.abc.PathEntryFinder.invalidate_caches "importlib.abc.PathEntryFinder.invalidate_caches") on all finders stored in [`sys.path_importer_cache`](sys.xhtml#sys.path_importer_cache "sys.path_importer_cache") that define the method. Otherwise entries in [`sys.path_importer_cache`](sys.xhtml#sys.path_importer_cache "sys.path_importer_cache") set to `None` are deleted.
在 3.7 版更改: Entries of `None` in [`sys.path_importer_cache`](sys.xhtml#sys.path_importer_cache "sys.path_importer_cache") are deleted.
在 3.4 版更改: Calls objects in [`sys.path_hooks`](sys.xhtml#sys.path_hooks "sys.path_hooks") with the current working directory for `''` (i.e. the empty string).
*class* `importlib.machinery.``FileFinder`(*path*, *\*loader\_details*)A concrete implementation of [`importlib.abc.PathEntryFinder`](#importlib.abc.PathEntryFinder "importlib.abc.PathEntryFinder") which caches results from the file system.
The *path* argument is the directory for which the finder is in charge of searching.
The *loader\_details* argument is a variable number of 2-item tuples each containing a loader and a sequence of file suffixes the loader recognizes. The loaders are expected to be callables which accept two arguments of the module's name and the path to the file found.
The finder will cache the directory contents as necessary, making stat calls for each module search to verify the cache is not outdated. Because cache staleness relies upon the granularity of the operating system's state information of the file system, there is a potential race condition of searching for a module, creating a new file, and then searching for the module the new file represents. If the operations happen fast enough to fit within the granularity of stat calls, then the module search will fail. To prevent this from happening, when you create a module dynamically, make sure to call [`importlib.invalidate_caches()`](#importlib.invalidate_caches "importlib.invalidate_caches").
3\.3 新版功能.
`path`The path the finder will search in.
`find_spec`(*fullname*, *target=None*)Attempt to find the spec to handle *fullname* within [`path`](#importlib.machinery.FileFinder.path "importlib.machinery.FileFinder.path").
3\.4 新版功能.
`find_loader`(*fullname*)Attempt to find the loader to handle *fullname* within [`path`](#importlib.machinery.FileFinder.path "importlib.machinery.FileFinder.path").
`invalidate_caches`()Clear out the internal cache.
*classmethod* `path_hook`(*\*loader\_details*)A class method which returns a closure for use on [`sys.path_hooks`](sys.xhtml#sys.path_hooks "sys.path_hooks"). An instance of [`FileFinder`](#importlib.machinery.FileFinder "importlib.machinery.FileFinder") is returned by the closure using the path argument given to the closure directly and *loader\_details*indirectly.
If the argument to the closure is not an existing directory, [`ImportError`](exceptions.xhtml#ImportError "ImportError") is raised.
*class* `importlib.machinery.``SourceFileLoader`(*fullname*, *path*)A concrete implementation of [`importlib.abc.SourceLoader`](#importlib.abc.SourceLoader "importlib.abc.SourceLoader") by subclassing [`importlib.abc.FileLoader`](#importlib.abc.FileLoader "importlib.abc.FileLoader") and providing some concrete implementations of other methods.
3\.3 新版功能.
`name`The name of the module that this loader will handle.
`path`The path to the source file.
`is_package`(*fullname*)Return true if [`path`](#importlib.machinery.SourceFileLoader.path "importlib.machinery.SourceFileLoader.path") appears to be for a package.
`path_stats`(*path*)Concrete implementation of [`importlib.abc.SourceLoader.path_stats()`](#importlib.abc.SourceLoader.path_stats "importlib.abc.SourceLoader.path_stats").
`set_data`(*path*, *data*)Concrete implementation of [`importlib.abc.SourceLoader.set_data()`](#importlib.abc.SourceLoader.set_data "importlib.abc.SourceLoader.set_data").
`load_module`(*name=None*)Concrete implementation of [`importlib.abc.Loader.load_module()`](#importlib.abc.Loader.load_module "importlib.abc.Loader.load_module") where specifying the name of the module to load is optional.
3\.6 版后已移除: Use [`importlib.abc.Loader.exec_module()`](#importlib.abc.Loader.exec_module "importlib.abc.Loader.exec_module") instead.
*class* `importlib.machinery.``SourcelessFileLoader`(*fullname*, *path*)A concrete implementation of [`importlib.abc.FileLoader`](#importlib.abc.FileLoader "importlib.abc.FileLoader") which can import bytecode files (i.e. no source code files exist).
Please note that direct use of bytecode files (and thus not source code files) inhibits your modules from being usable by all Python implementations or new versions of Python which change the bytecode format.
3\.3 新版功能.
`name`The name of the module the loader will handle.
`path`The path to the bytecode file.
`is_package`(*fullname*)Determines if the module is a package based on [`path`](#importlib.machinery.SourcelessFileLoader.path "importlib.machinery.SourcelessFileLoader.path").
`get_code`(*fullname*)Returns the code object for [`name`](#importlib.machinery.SourcelessFileLoader.name "importlib.machinery.SourcelessFileLoader.name") created from [`path`](#importlib.machinery.SourcelessFileLoader.path "importlib.machinery.SourcelessFileLoader.path").
`get_source`(*fullname*)Returns `None` as bytecode files have no source when this loader is used.
`load_module`(*name=None*)Concrete implementation of [`importlib.abc.Loader.load_module()`](#importlib.abc.Loader.load_module "importlib.abc.Loader.load_module") where specifying the name of the module to load is optional.
3\.6 版后已移除: Use [`importlib.abc.Loader.exec_module()`](#importlib.abc.Loader.exec_module "importlib.abc.Loader.exec_module") instead.
*class* `importlib.machinery.``ExtensionFileLoader`(*fullname*, *path*)A concrete implementation of [`importlib.abc.ExecutionLoader`](#importlib.abc.ExecutionLoader "importlib.abc.ExecutionLoader") for extension modules.
The *fullname* argument specifies the name of the module the loader is to support. The *path* argument is the path to the extension module's file.
3\.3 新版功能.
`name`Name of the module the loader supports.
`path`Path to the extension module.
`create_module`(*spec*)Creates the module object from the given specification in accordance with [**PEP 489**](https://www.python.org/dev/peps/pep-0489) \[https://www.python.org/dev/peps/pep-0489\].
3\.5 新版功能.
`exec_module`(*module*)Initializes the given module object in accordance with [**PEP 489**](https://www.python.org/dev/peps/pep-0489) \[https://www.python.org/dev/peps/pep-0489\].
3\.5 新版功能.
`is_package`(*fullname*)Returns `True` if the file path points to a package's `__init__`module based on [`EXTENSION_SUFFIXES`](#importlib.machinery.EXTENSION_SUFFIXES "importlib.machinery.EXTENSION_SUFFIXES").
`get_code`(*fullname*)Returns `None` as extension modules lack a code object.
`get_source`(*fullname*)Returns `None` as extension modules do not have source code.
`get_filename`(*fullname*)Returns [`path`](#importlib.machinery.ExtensionFileLoader.path "importlib.machinery.ExtensionFileLoader.path").
3\.4 新版功能.
*class* `importlib.machinery.``ModuleSpec`(*name*, *loader*, *\**, *origin=None*, *loader\_state=None*, *is\_package=None*)A specification for a module's import-system-related state. This is typically exposed as the module's `__spec__` attribute. In the descriptions below, the names in parentheses give the corresponding attribute available directly on the module object. E.g. `module.__spec__.origin == module.__file__`. Note however that while the *values* are usually equivalent, they can differ since there is no synchronization between the two objects. Thus it is possible to update the module's `__path__` at runtime, and this will not be automatically reflected in `__spec__.submodule_search_locations`.
3\.4 新版功能.
`name`(`__name__`)
A string for the fully-qualified name of the module.
`loader`(`__loader__`)
The loader to use for loading. For namespace packages this should be set to `None`.
`origin`(`__file__`)
Name of the place from which the module is loaded, e.g. "builtin" for built-in modules and the filename for modules loaded from source. Normally "origin" should be set, but it may be `None` (the default) which indicates it is unspecified (e.g. for namespace packages).
`submodule_search_locations`(`__path__`)
List of strings for where to find submodules, if a package (`None`otherwise).
`loader_state`Container of extra module-specific data for use during loading (or `None`).
`cached`(`__cached__`)
String for where the compiled module should be stored (or `None`).
`parent`(`__package__`)
(Read-only) Fully-qualified name of the package to which the module belongs as a submodule (or `None`).
`has_location`Boolean indicating whether or not the module's "origin" attribute refers to a loadable location.
## [`importlib.util`](#module-importlib.util "importlib.util: Utility code for importers") -- Utility code for importers
**Source code:** [Lib/importlib/util.py](https://github.com/python/cpython/tree/3.7/Lib/importlib/util.py) \[https://github.com/python/cpython/tree/3.7/Lib/importlib/util.py\]
- - - - - -
This module contains the various objects that help in the construction of an [importer](../glossary.xhtml#term-importer).
`importlib.util.``MAGIC_NUMBER`The bytes which represent the bytecode version number. If you need help with loading/writing bytecode then consider [`importlib.abc.SourceLoader`](#importlib.abc.SourceLoader "importlib.abc.SourceLoader").
3\.4 新版功能.
`importlib.util.``cache_from_source`(*path*, *debug\_override=None*, *\**, *optimization=None*)Return the [**PEP 3147**](https://www.python.org/dev/peps/pep-3147) \[https://www.python.org/dev/peps/pep-3147\]/[**PEP 488**](https://www.python.org/dev/peps/pep-0488) \[https://www.python.org/dev/peps/pep-0488\] path to the byte-compiled file associated with the source *path*. For example, if *path* is `/foo/bar/baz.py` the return value would be `/foo/bar/__pycache__/baz.cpython-32.pyc` for Python 3.2. The `cpython-32` string comes from the current magic tag (see `get_tag()`; if `sys.implementation.cache_tag` is not defined then [`NotImplementedError`](exceptions.xhtml#NotImplementedError "NotImplementedError") will be raised).
The *optimization* parameter is used to specify the optimization level of the bytecode file. An empty string represents no optimization, so `/foo/bar/baz.py` with an *optimization* of `''` will result in a bytecode path of `/foo/bar/__pycache__/baz.cpython-32.pyc`. `None` causes the interpter's optimization level to be used. Any other value's string representation being used, so `/foo/bar/baz.py` with an *optimization* of `2` will lead to the bytecode path of `/foo/bar/__pycache__/baz.cpython-32.opt-2.pyc`. The string representation of *optimization* can only be alphanumeric, else [`ValueError`](exceptions.xhtml#ValueError "ValueError") is raised.
The *debug\_override* parameter is deprecated and can be used to override the system's value for `__debug__`. A `True` value is the equivalent of setting *optimization* to the empty string. A `False` value is the same as setting *optimization* to `1`. If both *debug\_override* an *optimization*are not `None` then [`TypeError`](exceptions.xhtml#TypeError "TypeError") is raised.
3\.4 新版功能.
在 3.5 版更改: The *optimization* parameter was added and the *debug\_override* parameter was deprecated.
在 3.6 版更改: 接受一個 [類路徑對象](../glossary.xhtml#term-path-like-object)。
`importlib.util.``source_from_cache`(*path*)Given the *path* to a [**PEP 3147**](https://www.python.org/dev/peps/pep-3147) \[https://www.python.org/dev/peps/pep-3147\] file name, return the associated source code file path. For example, if *path* is `/foo/bar/__pycache__/baz.cpython-32.pyc` the returned path would be `/foo/bar/baz.py`. *path* need not exist, however if it does not conform to [**PEP 3147**](https://www.python.org/dev/peps/pep-3147) \[https://www.python.org/dev/peps/pep-3147\] or [**PEP 488**](https://www.python.org/dev/peps/pep-0488) \[https://www.python.org/dev/peps/pep-0488\] format, a [`ValueError`](exceptions.xhtml#ValueError "ValueError") is raised. If `sys.implementation.cache_tag` is not defined, [`NotImplementedError`](exceptions.xhtml#NotImplementedError "NotImplementedError") is raised.
3\.4 新版功能.
在 3.6 版更改: 接受一個 [類路徑對象](../glossary.xhtml#term-path-like-object)。
`importlib.util.``decode_source`(*source\_bytes*)Decode the given bytes representing source code and return it as a string with universal newlines (as required by [`importlib.abc.InspectLoader.get_source()`](#importlib.abc.InspectLoader.get_source "importlib.abc.InspectLoader.get_source")).
3\.4 新版功能.
`importlib.util.``resolve_name`(*name*, *package*)Resolve a relative module name to an absolute one.
If **name** has no leading dots, then **name** is simply returned. This allows for usage such as `importlib.util.resolve_name('sys', __package__)` without doing a check to see if the **package** argument is needed.
[`ValueError`](exceptions.xhtml#ValueError "ValueError") is raised if **name** is a relative module name but package is a false value (e.g. `None` or the empty string). [`ValueError`](exceptions.xhtml#ValueError "ValueError") is also raised a relative name would escape its containing package (e.g. requesting `..bacon` from within the `spam` package).
3\.3 新版功能.
`importlib.util.``find_spec`(*name*, *package=None*)Find the [spec](../glossary.xhtml#term-module-spec) for a module, optionally relative to the specified **package** name. If the module is in [`sys.modules`](sys.xhtml#sys.modules "sys.modules"), then `sys.modules[name].__spec__` is returned (unless the spec would be `None` or is not set, in which case [`ValueError`](exceptions.xhtml#ValueError "ValueError") is raised). Otherwise a search using [`sys.meta_path`](sys.xhtml#sys.meta_path "sys.meta_path") is done. `None` is returned if no spec is found.
If **name** is for a submodule (contains a dot), the parent module is automatically imported.
**name** and **package** work the same as for `import_module()`.
3\.4 新版功能.
在 3.7 版更改: Raises [`ModuleNotFoundError`](exceptions.xhtml#ModuleNotFoundError "ModuleNotFoundError") instead of [`AttributeError`](exceptions.xhtml#AttributeError "AttributeError") if **package** is in fact not a package (i.e. lacks a [`__path__`](../reference/import.xhtml#__path__ "__path__")attribute).
`importlib.util.``module_from_spec`(*spec*)Create a new module based on **spec** and [`spec.loader.create_module`](#importlib.abc.Loader.create_module "importlib.abc.Loader.create_module").
If [`spec.loader.create_module`](#importlib.abc.Loader.create_module "importlib.abc.Loader.create_module")does not return `None`, then any pre-existing attributes will not be reset. Also, no [`AttributeError`](exceptions.xhtml#AttributeError "AttributeError") will be raised if triggered while accessing **spec** or setting an attribute on the module.
This function is preferred over using [`types.ModuleType`](types.xhtml#types.ModuleType "types.ModuleType") to create a new module as **spec** is used to set as many import-controlled attributes on the module as possible.
3\.5 新版功能.
`@``importlib.util.``module_for_loader`A [decorator](../glossary.xhtml#term-decorator) for [`importlib.abc.Loader.load_module()`](#importlib.abc.Loader.load_module "importlib.abc.Loader.load_module")to handle selecting the proper module object to load with. The decorated method is expected to have a call signature taking two positional arguments (e.g. `load_module(self, module)`) for which the second argument will be the module **object** to be used by the loader. Note that the decorator will not work on static methods because of the assumption of two arguments.
The decorated method will take in the **name** of the module to be loaded as expected for a [loader](../glossary.xhtml#term-loader). If the module is not found in [`sys.modules`](sys.xhtml#sys.modules "sys.modules") then a new one is constructed. Regardless of where the module came from, [`__loader__`](../reference/import.xhtml#__loader__ "__loader__") set to **self** and [`__package__`](../reference/import.xhtml#__package__ "__package__")is set based on what [`importlib.abc.InspectLoader.is_package()`](#importlib.abc.InspectLoader.is_package "importlib.abc.InspectLoader.is_package") returns (if available). These attributes are set unconditionally to support reloading.
If an exception is raised by the decorated method and a module was added to [`sys.modules`](sys.xhtml#sys.modules "sys.modules"), then the module will be removed to prevent a partially initialized module from being in left in [`sys.modules`](sys.xhtml#sys.modules "sys.modules"). If the module was already in [`sys.modules`](sys.xhtml#sys.modules "sys.modules") then it is left alone.
在 3.3 版更改: [`__loader__`](../reference/import.xhtml#__loader__ "__loader__") and [`__package__`](../reference/import.xhtml#__package__ "__package__") are automatically set (when possible).
在 3.4 版更改: Set [`__name__`](../reference/import.xhtml#__name__ "__name__"), [`__loader__`](../reference/import.xhtml#__loader__ "__loader__") [`__package__`](../reference/import.xhtml#__package__ "__package__")unconditionally to support reloading.
3\.4 版后已移除: The import machinery now directly performs all the functionality provided by this function.
`@``importlib.util.``set_loader`A [decorator](../glossary.xhtml#term-decorator) for [`importlib.abc.Loader.load_module()`](#importlib.abc.Loader.load_module "importlib.abc.Loader.load_module")to set the [`__loader__`](../reference/import.xhtml#__loader__ "__loader__")attribute on the returned module. If the attribute is already set the decorator does nothing. It is assumed that the first positional argument to the wrapped method (i.e. `self`) is what [`__loader__`](../reference/import.xhtml#__loader__ "__loader__") should be set to.
在 3.4 版更改: Set `__loader__` if set to `None`, as if the attribute does not exist.
3\.4 版后已移除: The import machinery takes care of this automatically.
`@``importlib.util.``set_package`A [decorator](../glossary.xhtml#term-decorator) for [`importlib.abc.Loader.load_module()`](#importlib.abc.Loader.load_module "importlib.abc.Loader.load_module") to set the [`__package__`](../reference/import.xhtml#__package__ "__package__") attribute on the returned module. If [`__package__`](../reference/import.xhtml#__package__ "__package__")is set and has a value other than `None` it will not be changed.
3\.4 版后已移除: The import machinery takes care of this automatically.
`importlib.util.``spec_from_loader`(*name*, *loader*, *\**, *origin=None*, *is\_package=None*)A factory function for creating a `ModuleSpec` instance based on a loader. The parameters have the same meaning as they do for ModuleSpec. The function uses available [loader](../glossary.xhtml#term-loader) APIs, such as `InspectLoader.is_package()`, to fill in any missing information on the spec.
3\.4 新版功能.
`importlib.util.``spec_from_file_location`(*name*, *location*, *\**, *loader=None*, *submodule\_search\_locations=None*)A factory function for creating a `ModuleSpec` instance based on the path to a file. Missing information will be filled in on the spec by making use of loader APIs and by the implication that the module will be file-based.
3\.4 新版功能.
在 3.6 版更改: 接受一個 [類路徑對象](../glossary.xhtml#term-path-like-object)。
`importlib.util.``source_hash`(*source\_bytes*)Return the hash of *source\_bytes* as bytes. A hash-based `.pyc` file embeds the [`source_hash()`](#importlib.util.source_hash "importlib.util.source_hash") of the corresponding source file's contents in its header.
3\.7 新版功能.
*class* `importlib.util.``LazyLoader`(*loader*)A class which postpones the execution of the loader of a module until the module has an attribute accessed.
This class **only** works with loaders that define [`exec_module()`](#importlib.abc.Loader.exec_module "importlib.abc.Loader.exec_module") as control over what module type is used for the module is required. For those same reasons, the loader's [`create_module()`](#importlib.abc.Loader.create_module "importlib.abc.Loader.create_module") method must return `None` or a type for which its `__class__` attribute can be mutated along with not using [slots](../glossary.xhtml#term-slots). Finally, modules which substitute the object placed into [`sys.modules`](sys.xhtml#sys.modules "sys.modules") will not work as there is no way to properly replace the module references throughout the interpreter safely; [`ValueError`](exceptions.xhtml#ValueError "ValueError") is raised if such a substitution is detected.
注解
For projects where startup time is critical, this class allows for potentially minimizing the cost of loading a module if it is never used. For projects where startup time is not essential then use of this class is **heavily** discouraged due to error messages created during loading being postponed and thus occurring out of context.
3\.5 新版功能.
在 3.6 版更改: Began calling [`create_module()`](#importlib.abc.Loader.create_module "importlib.abc.Loader.create_module"), removing the compatibility warning for [`importlib.machinery.BuiltinImporter`](#importlib.machinery.BuiltinImporter "importlib.machinery.BuiltinImporter") and [`importlib.machinery.ExtensionFileLoader`](#importlib.machinery.ExtensionFileLoader "importlib.machinery.ExtensionFileLoader").
*classmethod* `factory`(*loader*)A static method which returns a callable that creates a lazy loader. This is meant to be used in situations where the loader is passed by class instead of by instance.
```
suffixes = importlib.machinery.SOURCE_SUFFIXES
loader = importlib.machinery.SourceFileLoader
lazy_loader = importlib.util.LazyLoader.factory(loader)
finder = importlib.machinery.FileFinder(path, (lazy_loader, suffixes))
```
## 示例
### Importing programmatically
To programmatically import a module, use [`importlib.import_module()`](#importlib.import_module "importlib.import_module").
```
import importlib
itertools = importlib.import_module('itertools')
```
### Checking if a module can be imported
If you need to find out if a module can be imported without actually doing the import, then you should use [`importlib.util.find_spec()`](#importlib.util.find_spec "importlib.util.find_spec").
```
import importlib.util
import sys
# For illustrative purposes.
name = 'itertools'
spec = importlib.util.find_spec(name)
if spec is None:
print("can't find the itertools module")
else:
# If you chose to perform the actual import ...
module = importlib.util.module_from_spec(spec)
spec.loader.exec_module(module)
# Adding the module to sys.modules is optional.
sys.modules[name] = module
```
### Importing a source file directly
To import a Python source file directly, use the following recipe (Python 3.5 and newer only):
```
import importlib.util
import sys
# For illustrative purposes.
import tokenize
file_path = tokenize.__file__
module_name = tokenize.__name__
spec = importlib.util.spec_from_file_location(module_name, file_path)
module = importlib.util.module_from_spec(spec)
spec.loader.exec_module(module)
# Optional; only necessary if you want to be able to import the module
# by name later.
sys.modules[module_name] = module
```
### Setting up an importer
For deep customizations of import, you typically want to implement an [importer](../glossary.xhtml#term-importer). This means managing both the [finder](../glossary.xhtml#term-finder) and [loader](../glossary.xhtml#term-loader)side of things. For finders there are two flavours to choose from depending on your needs: a [meta path finder](../glossary.xhtml#term-meta-path-finder) or a [path entry finder](../glossary.xhtml#term-path-entry-finder). The former is what you would put on [`sys.meta_path`](sys.xhtml#sys.meta_path "sys.meta_path") while the latter is what you create using a [path entry hook](../glossary.xhtml#term-path-entry-hook) on [`sys.path_hooks`](sys.xhtml#sys.path_hooks "sys.path_hooks") which works with [`sys.path`](sys.xhtml#sys.path "sys.path") entries to potentially create a finder. This example will show you how to register your own importers so that import will use them (for creating an importer for yourself, read the documentation for the appropriate classes defined within this package):
```
import importlib.machinery
import sys
# For illustrative purposes only.
SpamMetaPathFinder = importlib.machinery.PathFinder
SpamPathEntryFinder = importlib.machinery.FileFinder
loader_details = (importlib.machinery.SourceFileLoader,
importlib.machinery.SOURCE_SUFFIXES)
# Setting up a meta path finder.
# Make sure to put the finder in the proper location in the list in terms of
# priority.
sys.meta_path.append(SpamMetaPathFinder)
# Setting up a path entry finder.
# Make sure to put the path hook in the proper location in the list in terms
# of priority.
sys.path_hooks.append(SpamPathEntryFinder.path_hook(loader_details))
```
### Approximating [`importlib.import_module()`](#importlib.import_module "importlib.import_module")
Import itself is implemented in Python code, making it possible to expose most of the import machinery through importlib. The following helps illustrate the various APIs that importlib exposes by providing an approximate implementation of [`importlib.import_module()`](#importlib.import_module "importlib.import_module") (Python 3.4 and newer for the importlib usage, Python 3.6 and newer for other parts of the code).
```
import importlib.util
import sys
def import_module(name, package=None):
"""An approximate implementation of import."""
absolute_name = importlib.util.resolve_name(name, package)
try:
return sys.modules[absolute_name]
except KeyError:
pass
path = None
if '.' in absolute_name:
parent_name, _, child_name = absolute_name.rpartition('.')
parent_module = import_module(parent_name)
path = parent_module.__spec__.submodule_search_locations
for finder in sys.meta_path:
spec = finder.find_spec(absolute_name, path)
if spec is not None:
break
else:
msg = f'No module named {absolute_name!r}'
raise ModuleNotFoundError(msg, name=absolute_name)
module = importlib.util.module_from_spec(spec)
spec.loader.exec_module(module)
sys.modules[absolute_name] = module
if path is not None:
setattr(parent_module, child_name, module)
return module
```
### 導航
- [索引](../genindex.xhtml "總目錄")
- [模塊](../py-modindex.xhtml "Python 模塊索引") |
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- [Python](https://www.python.org/) ?
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- Python文檔內容
- Python 有什么新變化?
- Python 3.7 有什么新變化
- 摘要 - 發布重點
- 新的特性
- 其他語言特性修改
- 新增模塊
- 改進的模塊
- C API 的改變
- 構建的改變
- 性能優化
- 其他 CPython 實現的改變
- 已棄用的 Python 行為
- 已棄用的 Python 模塊、函數和方法
- 已棄用的 C API 函數和類型
- 平臺支持的移除
- API 與特性的移除
- 移除的模塊
- Windows 專屬的改變
- 移植到 Python 3.7
- Python 3.7.1 中的重要變化
- Python 3.7.2 中的重要變化
- Python 3.6 有什么新變化A
- 摘要 - 發布重點
- 新的特性
- 其他語言特性修改
- 新增模塊
- 改進的模塊
- 性能優化
- Build and C API Changes
- 其他改進
- 棄用
- 移除
- 移植到Python 3.6
- Python 3.6.2 中的重要變化
- Python 3.6.4 中的重要變化
- Python 3.6.5 中的重要變化
- Python 3.6.7 中的重要變化
- Python 3.5 有什么新變化
- 摘要 - 發布重點
- 新的特性
- 其他語言特性修改
- 新增模塊
- 改進的模塊
- Other module-level changes
- 性能優化
- Build and C API Changes
- 棄用
- 移除
- Porting to Python 3.5
- Notable changes in Python 3.5.4
- What's New In Python 3.4
- 摘要 - 發布重點
- 新的特性
- 新增模塊
- 改進的模塊
- CPython Implementation Changes
- 棄用
- 移除
- Porting to Python 3.4
- Changed in 3.4.3
- What's New In Python 3.3
- 摘要 - 發布重點
- PEP 405: Virtual Environments
- PEP 420: Implicit Namespace Packages
- PEP 3118: New memoryview implementation and buffer protocol documentation
- PEP 393: Flexible String Representation
- PEP 397: Python Launcher for Windows
- PEP 3151: Reworking the OS and IO exception hierarchy
- PEP 380: Syntax for Delegating to a Subgenerator
- PEP 409: Suppressing exception context
- PEP 414: Explicit Unicode literals
- PEP 3155: Qualified name for classes and functions
- PEP 412: Key-Sharing Dictionary
- PEP 362: Function Signature Object
- PEP 421: Adding sys.implementation
- Using importlib as the Implementation of Import
- 其他語言特性修改
- A Finer-Grained Import Lock
- Builtin functions and types
- 新增模塊
- 改進的模塊
- 性能優化
- Build and C API Changes
- 棄用
- Porting to Python 3.3
- What's New In Python 3.2
- PEP 384: Defining a Stable ABI
- PEP 389: Argparse Command Line Parsing Module
- PEP 391: Dictionary Based Configuration for Logging
- PEP 3148: The concurrent.futures module
- PEP 3147: PYC Repository Directories
- PEP 3149: ABI Version Tagged .so Files
- PEP 3333: Python Web Server Gateway Interface v1.0.1
- 其他語言特性修改
- New, Improved, and Deprecated Modules
- 多線程
- 性能優化
- Unicode
- Codecs
- 文檔
- IDLE
- Code Repository
- Build and C API Changes
- Porting to Python 3.2
- What's New In Python 3.1
- PEP 372: Ordered Dictionaries
- PEP 378: Format Specifier for Thousands Separator
- 其他語言特性修改
- New, Improved, and Deprecated Modules
- 性能優化
- IDLE
- Build and C API Changes
- Porting to Python 3.1
- What's New In Python 3.0
- Common Stumbling Blocks
- Overview Of Syntax Changes
- Changes Already Present In Python 2.6
- Library Changes
- PEP 3101: A New Approach To String Formatting
- Changes To Exceptions
- Miscellaneous Other Changes
- Build and C API Changes
- 性能
- Porting To Python 3.0
- What's New in Python 2.7
- The Future for Python 2.x
- Changes to the Handling of Deprecation Warnings
- Python 3.1 Features
- PEP 372: Adding an Ordered Dictionary to collections
- PEP 378: Format Specifier for Thousands Separator
- PEP 389: The argparse Module for Parsing Command Lines
- PEP 391: Dictionary-Based Configuration For Logging
- PEP 3106: Dictionary Views
- PEP 3137: The memoryview Object
- 其他語言特性修改
- New and Improved Modules
- Build and C API Changes
- Other Changes and Fixes
- Porting to Python 2.7
- New Features Added to Python 2.7 Maintenance Releases
- Acknowledgements
- Python 2.6 有什么新變化
- Python 3.0
- Changes to the Development Process
- PEP 343: The 'with' statement
- PEP 366: Explicit Relative Imports From a Main Module
- PEP 370: Per-user site-packages Directory
- PEP 371: The multiprocessing Package
- PEP 3101: Advanced String Formatting
- PEP 3105: print As a Function
- PEP 3110: Exception-Handling Changes
- PEP 3112: Byte Literals
- PEP 3116: New I/O Library
- PEP 3118: Revised Buffer Protocol
- PEP 3119: Abstract Base Classes
- PEP 3127: Integer Literal Support and Syntax
- PEP 3129: Class Decorators
- PEP 3141: A Type Hierarchy for Numbers
- 其他語言特性修改
- New and Improved Modules
- Deprecations and Removals
- Build and C API Changes
- Porting to Python 2.6
- Acknowledgements
- What's New in Python 2.5
- PEP 308: Conditional Expressions
- PEP 309: Partial Function Application
- PEP 314: Metadata for Python Software Packages v1.1
- PEP 328: Absolute and Relative Imports
- PEP 338: Executing Modules as Scripts
- PEP 341: Unified try/except/finally
- PEP 342: New Generator Features
- PEP 343: The 'with' statement
- PEP 352: Exceptions as New-Style Classes
- PEP 353: Using ssize_t as the index type
- PEP 357: The 'index' method
- 其他語言特性修改
- New, Improved, and Removed Modules
- Build and C API Changes
- Porting to Python 2.5
- Acknowledgements
- What's New in Python 2.4
- PEP 218: Built-In Set Objects
- PEP 237: Unifying Long Integers and Integers
- PEP 289: Generator Expressions
- PEP 292: Simpler String Substitutions
- PEP 318: Decorators for Functions and Methods
- PEP 322: Reverse Iteration
- PEP 324: New subprocess Module
- PEP 327: Decimal Data Type
- PEP 328: Multi-line Imports
- PEP 331: Locale-Independent Float/String Conversions
- 其他語言特性修改
- New, Improved, and Deprecated Modules
- Build and C API Changes
- Porting to Python 2.4
- Acknowledgements
- What's New in Python 2.3
- PEP 218: A Standard Set Datatype
- PEP 255: Simple Generators
- PEP 263: Source Code Encodings
- PEP 273: Importing Modules from ZIP Archives
- PEP 277: Unicode file name support for Windows NT
- PEP 278: Universal Newline Support
- PEP 279: enumerate()
- PEP 282: The logging Package
- PEP 285: A Boolean Type
- PEP 293: Codec Error Handling Callbacks
- PEP 301: Package Index and Metadata for Distutils
- PEP 302: New Import Hooks
- PEP 305: Comma-separated Files
- PEP 307: Pickle Enhancements
- Extended Slices
- 其他語言特性修改
- New, Improved, and Deprecated Modules
- Pymalloc: A Specialized Object Allocator
- Build and C API Changes
- Other Changes and Fixes
- Porting to Python 2.3
- Acknowledgements
- What's New in Python 2.2
- 概述
- PEPs 252 and 253: Type and Class Changes
- PEP 234: Iterators
- PEP 255: Simple Generators
- PEP 237: Unifying Long Integers and Integers
- PEP 238: Changing the Division Operator
- Unicode Changes
- PEP 227: Nested Scopes
- New and Improved Modules
- Interpreter Changes and Fixes
- Other Changes and Fixes
- Acknowledgements
- What's New in Python 2.1
- 概述
- PEP 227: Nested Scopes
- PEP 236: future Directives
- PEP 207: Rich Comparisons
- PEP 230: Warning Framework
- PEP 229: New Build System
- PEP 205: Weak References
- PEP 232: Function Attributes
- PEP 235: Importing Modules on Case-Insensitive Platforms
- PEP 217: Interactive Display Hook
- PEP 208: New Coercion Model
- PEP 241: Metadata in Python Packages
- New and Improved Modules
- Other Changes and Fixes
- Acknowledgements
- What's New in Python 2.0
- 概述
- What About Python 1.6?
- New Development Process
- Unicode
- 列表推導式
- Augmented Assignment
- 字符串的方法
- Garbage Collection of Cycles
- Other Core Changes
- Porting to 2.0
- Extending/Embedding Changes
- Distutils: Making Modules Easy to Install
- XML Modules
- Module changes
- New modules
- IDLE Improvements
- Deleted and Deprecated Modules
- Acknowledgements
- 更新日志
- Python 下一版
- Python 3.7.3 最終版
- Python 3.7.3 發布候選版 1
- Python 3.7.2 最終版
- Python 3.7.2 發布候選版 1
- Python 3.7.1 最終版
- Python 3.7.1 RC 2版本
- Python 3.7.1 發布候選版 1
- Python 3.7.0 正式版
- Python 3.7.0 release candidate 1
- Python 3.7.0 beta 5
- Python 3.7.0 beta 4
- Python 3.7.0 beta 3
- Python 3.7.0 beta 2
- Python 3.7.0 beta 1
- Python 3.7.0 alpha 4
- Python 3.7.0 alpha 3
- Python 3.7.0 alpha 2
- Python 3.7.0 alpha 1
- Python 3.6.6 final
- Python 3.6.6 RC 1
- Python 3.6.5 final
- Python 3.6.5 release candidate 1
- Python 3.6.4 final
- Python 3.6.4 release candidate 1
- Python 3.6.3 final
- Python 3.6.3 release candidate 1
- Python 3.6.2 final
- Python 3.6.2 release candidate 2
- Python 3.6.2 release candidate 1
- Python 3.6.1 final
- Python 3.6.1 release candidate 1
- Python 3.6.0 final
- Python 3.6.0 release candidate 2
- Python 3.6.0 release candidate 1
- Python 3.6.0 beta 4
- Python 3.6.0 beta 3
- Python 3.6.0 beta 2
- Python 3.6.0 beta 1
- Python 3.6.0 alpha 4
- Python 3.6.0 alpha 3
- Python 3.6.0 alpha 2
- Python 3.6.0 alpha 1
- Python 3.5.5 final
- Python 3.5.5 release candidate 1
- Python 3.5.4 final
- Python 3.5.4 release candidate 1
- Python 3.5.3 final
- Python 3.5.3 release candidate 1
- Python 3.5.2 final
- Python 3.5.2 release candidate 1
- Python 3.5.1 final
- Python 3.5.1 release candidate 1
- Python 3.5.0 final
- Python 3.5.0 release candidate 4
- Python 3.5.0 release candidate 3
- Python 3.5.0 release candidate 2
- Python 3.5.0 release candidate 1
- Python 3.5.0 beta 4
- Python 3.5.0 beta 3
- Python 3.5.0 beta 2
- Python 3.5.0 beta 1
- Python 3.5.0 alpha 4
- Python 3.5.0 alpha 3
- Python 3.5.0 alpha 2
- Python 3.5.0 alpha 1
- Python 教程
- 課前甜點
- 使用 Python 解釋器
- 調用解釋器
- 解釋器的運行環境
- Python 的非正式介紹
- Python 作為計算器使用
- 走向編程的第一步
- 其他流程控制工具
- if 語句
- for 語句
- range() 函數
- break 和 continue 語句,以及循環中的 else 子句
- pass 語句
- 定義函數
- 函數定義的更多形式
- 小插曲:編碼風格
- 數據結構
- 列表的更多特性
- del 語句
- 元組和序列
- 集合
- 字典
- 循環的技巧
- 深入條件控制
- 序列和其它類型的比較
- 模塊
- 有關模塊的更多信息
- 標準模塊
- dir() 函數
- 包
- 輸入輸出
- 更漂亮的輸出格式
- 讀寫文件
- 錯誤和異常
- 語法錯誤
- 異常
- 處理異常
- 拋出異常
- 用戶自定義異常
- 定義清理操作
- 預定義的清理操作
- 類
- 名稱和對象
- Python 作用域和命名空間
- 初探類
- 補充說明
- 繼承
- 私有變量
- 雜項說明
- 迭代器
- 生成器
- 生成器表達式
- 標準庫簡介
- 操作系統接口
- 文件通配符
- 命令行參數
- 錯誤輸出重定向和程序終止
- 字符串模式匹配
- 數學
- 互聯網訪問
- 日期和時間
- 數據壓縮
- 性能測量
- 質量控制
- 自帶電池
- 標準庫簡介 —— 第二部分
- 格式化輸出
- 模板
- 使用二進制數據記錄格式
- 多線程
- 日志
- 弱引用
- 用于操作列表的工具
- 十進制浮點運算
- 虛擬環境和包
- 概述
- 創建虛擬環境
- 使用pip管理包
- 接下來?
- 交互式編輯和編輯歷史
- Tab 補全和編輯歷史
- 默認交互式解釋器的替代品
- 浮點算術:爭議和限制
- 表示性錯誤
- 附錄
- 交互模式
- 安裝和使用 Python
- 命令行與環境
- 命令行
- 環境變量
- 在Unix平臺中使用Python
- 獲取最新版本的Python
- 構建Python
- 與Python相關的路徑和文件
- 雜項
- 編輯器和集成開發環境
- 在Windows上使用 Python
- 完整安裝程序
- Microsoft Store包
- nuget.org 安裝包
- 可嵌入的包
- 替代捆綁包
- 配置Python
- 適用于Windows的Python啟動器
- 查找模塊
- 附加模塊
- 在Windows上編譯Python
- 其他平臺
- 在蘋果系統上使用 Python
- 獲取和安裝 MacPython
- IDE
- 安裝額外的 Python 包
- Mac 上的圖形界面編程
- 在 Mac 上分發 Python 應用程序
- 其他資源
- Python 語言參考
- 概述
- 其他實現
- 標注
- 詞法分析
- 行結構
- 其他形符
- 標識符和關鍵字
- 字面值
- 運算符
- 分隔符
- 數據模型
- 對象、值與類型
- 標準類型層級結構
- 特殊方法名稱
- 協程
- 執行模型
- 程序的結構
- 命名與綁定
- 異常
- 導入系統
- importlib
- 包
- 搜索
- 加載
- 基于路徑的查找器
- 替換標準導入系統
- Package Relative Imports
- 有關 main 的特殊事項
- 開放問題項
- 參考文獻
- 表達式
- 算術轉換
- 原子
- 原型
- await 表達式
- 冪運算符
- 一元算術和位運算
- 二元算術運算符
- 移位運算
- 二元位運算
- 比較運算
- 布爾運算
- 條件表達式
- lambda 表達式
- 表達式列表
- 求值順序
- 運算符優先級
- 簡單語句
- 表達式語句
- 賦值語句
- assert 語句
- pass 語句
- del 語句
- return 語句
- yield 語句
- raise 語句
- break 語句
- continue 語句
- import 語句
- global 語句
- nonlocal 語句
- 復合語句
- if 語句
- while 語句
- for 語句
- try 語句
- with 語句
- 函數定義
- 類定義
- 協程
- 最高層級組件
- 完整的 Python 程序
- 文件輸入
- 交互式輸入
- 表達式輸入
- 完整的語法規范
- Python 標準庫
- 概述
- 可用性注釋
- 內置函數
- 內置常量
- 由 site 模塊添加的常量
- 內置類型
- 邏輯值檢測
- 布爾運算 — and, or, not
- 比較
- 數字類型 — int, float, complex
- 迭代器類型
- 序列類型 — list, tuple, range
- 文本序列類型 — str
- 二進制序列類型 — bytes, bytearray, memoryview
- 集合類型 — set, frozenset
- 映射類型 — dict
- 上下文管理器類型
- 其他內置類型
- 特殊屬性
- 內置異常
- 基類
- 具體異常
- 警告
- 異常層次結構
- 文本處理服務
- string — 常見的字符串操作
- re — 正則表達式操作
- 模塊 difflib 是一個計算差異的助手
- textwrap — Text wrapping and filling
- unicodedata — Unicode 數據庫
- stringprep — Internet String Preparation
- readline — GNU readline interface
- rlcompleter — GNU readline的完成函數
- 二進制數據服務
- struct — Interpret bytes as packed binary data
- codecs — Codec registry and base classes
- 數據類型
- datetime — 基礎日期/時間數據類型
- calendar — General calendar-related functions
- collections — 容器數據類型
- collections.abc — 容器的抽象基類
- heapq — 堆隊列算法
- bisect — Array bisection algorithm
- array — Efficient arrays of numeric values
- weakref — 弱引用
- types — Dynamic type creation and names for built-in types
- copy — 淺層 (shallow) 和深層 (deep) 復制操作
- pprint — 數據美化輸出
- reprlib — Alternate repr() implementation
- enum — Support for enumerations
- 數字和數學模塊
- numbers — 數字的抽象基類
- math — 數學函數
- cmath — Mathematical functions for complex numbers
- decimal — 十進制定點和浮點運算
- fractions — 分數
- random — 生成偽隨機數
- statistics — Mathematical statistics functions
- 函數式編程模塊
- itertools — 為高效循環而創建迭代器的函數
- functools — 高階函數和可調用對象上的操作
- operator — 標準運算符替代函數
- 文件和目錄訪問
- pathlib — 面向對象的文件系統路徑
- os.path — 常見路徑操作
- fileinput — Iterate over lines from multiple input streams
- stat — Interpreting stat() results
- filecmp — File and Directory Comparisons
- tempfile — Generate temporary files and directories
- glob — Unix style pathname pattern expansion
- fnmatch — Unix filename pattern matching
- linecache — Random access to text lines
- shutil — High-level file operations
- macpath — Mac OS 9 路徑操作函數
- 數據持久化
- pickle —— Python 對象序列化
- copyreg — Register pickle support functions
- shelve — Python object persistence
- marshal — Internal Python object serialization
- dbm — Interfaces to Unix “databases”
- sqlite3 — SQLite 數據庫 DB-API 2.0 接口模塊
- 數據壓縮和存檔
- zlib — 與 gzip 兼容的壓縮
- gzip — 對 gzip 格式的支持
- bz2 — 對 bzip2 壓縮算法的支持
- lzma — 用 LZMA 算法壓縮
- zipfile — 在 ZIP 歸檔中工作
- tarfile — Read and write tar archive files
- 文件格式
- csv — CSV 文件讀寫
- configparser — Configuration file parser
- netrc — netrc file processing
- xdrlib — Encode and decode XDR data
- plistlib — Generate and parse Mac OS X .plist files
- 加密服務
- hashlib — 安全哈希與消息摘要
- hmac — 基于密鑰的消息驗證
- secrets — Generate secure random numbers for managing secrets
- 通用操作系統服務
- os — 操作系統接口模塊
- io — 處理流的核心工具
- time — 時間的訪問和轉換
- argparse — 命令行選項、參數和子命令解析器
- getopt — C-style parser for command line options
- 模塊 logging — Python 的日志記錄工具
- logging.config — 日志記錄配置
- logging.handlers — Logging handlers
- getpass — 便攜式密碼輸入工具
- curses — 終端字符單元顯示的處理
- curses.textpad — Text input widget for curses programs
- curses.ascii — Utilities for ASCII characters
- curses.panel — A panel stack extension for curses
- platform — Access to underlying platform's identifying data
- errno — Standard errno system symbols
- ctypes — Python 的外部函數庫
- 并發執行
- threading — 基于線程的并行
- multiprocessing — 基于進程的并行
- concurrent 包
- concurrent.futures — 啟動并行任務
- subprocess — 子進程管理
- sched — 事件調度器
- queue — 一個同步的隊列類
- _thread — 底層多線程 API
- _dummy_thread — _thread 的替代模塊
- dummy_threading — 可直接替代 threading 模塊。
- contextvars — Context Variables
- Context Variables
- Manual Context Management
- asyncio support
- 網絡和進程間通信
- asyncio — 異步 I/O
- socket — 底層網絡接口
- ssl — TLS/SSL wrapper for socket objects
- select — Waiting for I/O completion
- selectors — 高級 I/O 復用庫
- asyncore — 異步socket處理器
- asynchat — 異步 socket 指令/響應 處理器
- signal — Set handlers for asynchronous events
- mmap — Memory-mapped file support
- 互聯網數據處理
- email — 電子郵件與 MIME 處理包
- json — JSON 編碼和解碼器
- mailcap — Mailcap file handling
- mailbox — Manipulate mailboxes in various formats
- mimetypes — Map filenames to MIME types
- base64 — Base16, Base32, Base64, Base85 數據編碼
- binhex — 對binhex4文件進行編碼和解碼
- binascii — 二進制和 ASCII 碼互轉
- quopri — Encode and decode MIME quoted-printable data
- uu — Encode and decode uuencode files
- 結構化標記處理工具
- html — 超文本標記語言支持
- html.parser — 簡單的 HTML 和 XHTML 解析器
- html.entities — HTML 一般實體的定義
- XML處理模塊
- xml.etree.ElementTree — The ElementTree XML API
- xml.dom — The Document Object Model API
- xml.dom.minidom — Minimal DOM implementation
- xml.dom.pulldom — Support for building partial DOM trees
- xml.sax — Support for SAX2 parsers
- xml.sax.handler — Base classes for SAX handlers
- xml.sax.saxutils — SAX Utilities
- xml.sax.xmlreader — Interface for XML parsers
- xml.parsers.expat — Fast XML parsing using Expat
- 互聯網協議和支持
- webbrowser — 方便的Web瀏覽器控制器
- cgi — Common Gateway Interface support
- cgitb — Traceback manager for CGI scripts
- wsgiref — WSGI Utilities and Reference Implementation
- urllib — URL 處理模塊
- urllib.request — 用于打開 URL 的可擴展庫
- urllib.response — Response classes used by urllib
- urllib.parse — Parse URLs into components
- urllib.error — Exception classes raised by urllib.request
- urllib.robotparser — Parser for robots.txt
- http — HTTP 模塊
- http.client — HTTP協議客戶端
- ftplib — FTP protocol client
- poplib — POP3 protocol client
- imaplib — IMAP4 protocol client
- nntplib — NNTP protocol client
- smtplib —SMTP協議客戶端
- smtpd — SMTP Server
- telnetlib — Telnet client
- uuid — UUID objects according to RFC 4122
- socketserver — A framework for network servers
- http.server — HTTP 服務器
- http.cookies — HTTP state management
- http.cookiejar — Cookie handling for HTTP clients
- xmlrpc — XMLRPC 服務端與客戶端模塊
- xmlrpc.client — XML-RPC client access
- xmlrpc.server — Basic XML-RPC servers
- ipaddress — IPv4/IPv6 manipulation library
- 多媒體服務
- audioop — Manipulate raw audio data
- aifc — Read and write AIFF and AIFC files
- sunau — 讀寫 Sun AU 文件
- wave — 讀寫WAV格式文件
- chunk — Read IFF chunked data
- colorsys — Conversions between color systems
- imghdr — 推測圖像類型
- sndhdr — 推測聲音文件的類型
- ossaudiodev — Access to OSS-compatible audio devices
- 國際化
- gettext — 多語種國際化服務
- locale — 國際化服務
- 程序框架
- turtle — 海龜繪圖
- cmd — 支持面向行的命令解釋器
- shlex — Simple lexical analysis
- Tk圖形用戶界面(GUI)
- tkinter — Tcl/Tk的Python接口
- tkinter.ttk — Tk themed widgets
- tkinter.tix — Extension widgets for Tk
- tkinter.scrolledtext — 滾動文字控件
- IDLE
- 其他圖形用戶界面(GUI)包
- 開發工具
- typing — 類型標注支持
- pydoc — Documentation generator and online help system
- doctest — Test interactive Python examples
- unittest — 單元測試框架
- unittest.mock — mock object library
- unittest.mock 上手指南
- 2to3 - 自動將 Python 2 代碼轉為 Python 3 代碼
- test — Regression tests package for Python
- test.support — Utilities for the Python test suite
- test.support.script_helper — Utilities for the Python execution tests
- 調試和分析
- bdb — Debugger framework
- faulthandler — Dump the Python traceback
- pdb — The Python Debugger
- The Python Profilers
- timeit — 測量小代碼片段的執行時間
- trace — Trace or track Python statement execution
- tracemalloc — Trace memory allocations
- 軟件打包和分發
- distutils — 構建和安裝 Python 模塊
- ensurepip — Bootstrapping the pip installer
- venv — 創建虛擬環境
- zipapp — Manage executable Python zip archives
- Python運行時服務
- sys — 系統相關的參數和函數
- sysconfig — Provide access to Python's configuration information
- builtins — 內建對象
- main — 頂層腳本環境
- warnings — Warning control
- dataclasses — 數據類
- contextlib — Utilities for with-statement contexts
- abc — 抽象基類
- atexit — 退出處理器
- traceback — Print or retrieve a stack traceback
- future — Future 語句定義
- gc — 垃圾回收器接口
- inspect — 檢查對象
- site — Site-specific configuration hook
- 自定義 Python 解釋器
- code — Interpreter base classes
- codeop — Compile Python code
- 導入模塊
- zipimport — Import modules from Zip archives
- pkgutil — Package extension utility
- modulefinder — 查找腳本使用的模塊
- runpy — Locating and executing Python modules
- importlib — The implementation of import
- Python 語言服務
- parser — Access Python parse trees
- ast — 抽象語法樹
- symtable — Access to the compiler's symbol tables
- symbol — 與 Python 解析樹一起使用的常量
- token — 與Python解析樹一起使用的常量
- keyword — 檢驗Python關鍵字
- tokenize — Tokenizer for Python source
- tabnanny — 模糊縮進檢測
- pyclbr — Python class browser support
- py_compile — Compile Python source files
- compileall — Byte-compile Python libraries
- dis — Python 字節碼反匯編器
- pickletools — Tools for pickle developers
- 雜項服務
- formatter — Generic output formatting
- Windows系統相關模塊
- msilib — Read and write Microsoft Installer files
- msvcrt — Useful routines from the MS VC++ runtime
- winreg — Windows 注冊表訪問
- winsound — Sound-playing interface for Windows
- Unix 專有服務
- posix — The most common POSIX system calls
- pwd — 用戶密碼數據庫
- spwd — The shadow password database
- grp — The group database
- crypt — Function to check Unix passwords
- termios — POSIX style tty control
- tty — 終端控制功能
- pty — Pseudo-terminal utilities
- fcntl — The fcntl and ioctl system calls
- pipes — Interface to shell pipelines
- resource — Resource usage information
- nis — Interface to Sun's NIS (Yellow Pages)
- Unix syslog 庫例程
- 被取代的模塊
- optparse — Parser for command line options
- imp — Access the import internals
- 未創建文檔的模塊
- 平臺特定模塊
- 擴展和嵌入 Python 解釋器
- 推薦的第三方工具
- 不使用第三方工具創建擴展
- 使用 C 或 C++ 擴展 Python
- 自定義擴展類型:教程
- 定義擴展類型:已分類主題
- 構建C/C++擴展
- 在Windows平臺編譯C和C++擴展
- 在更大的應用程序中嵌入 CPython 運行時
- Embedding Python in Another Application
- Python/C API 參考手冊
- 概述
- 代碼標準
- 包含文件
- 有用的宏
- 對象、類型和引用計數
- 異常
- 嵌入Python
- 調試構建
- 穩定的應用程序二進制接口
- The Very High Level Layer
- Reference Counting
- 異常處理
- Printing and clearing
- 拋出異常
- Issuing warnings
- Querying the error indicator
- Signal Handling
- Exception Classes
- Exception Objects
- Unicode Exception Objects
- Recursion Control
- 標準異常
- 標準警告類別
- 工具
- 操作系統實用程序
- 系統功能
- 過程控制
- 導入模塊
- Data marshalling support
- 語句解釋及變量編譯
- 字符串轉換與格式化
- 反射
- 編解碼器注冊與支持功能
- 抽象對象層
- Object Protocol
- 數字協議
- Sequence Protocol
- Mapping Protocol
- 迭代器協議
- 緩沖協議
- Old Buffer Protocol
- 具體的對象層
- 基本對象
- 數值對象
- 序列對象
- 容器對象
- 函數對象
- 其他對象
- Initialization, Finalization, and Threads
- 在Python初始化之前
- 全局配置變量
- Initializing and finalizing the interpreter
- Process-wide parameters
- Thread State and the Global Interpreter Lock
- Sub-interpreter support
- Asynchronous Notifications
- Profiling and Tracing
- Advanced Debugger Support
- Thread Local Storage Support
- 內存管理
- 概述
- 原始內存接口
- Memory Interface
- 對象分配器
- 默認內存分配器
- Customize Memory Allocators
- The pymalloc allocator
- tracemalloc C API
- 示例
- 對象實現支持
- 在堆中分配對象
- Common Object Structures
- Type 對象
- Number Object Structures
- Mapping Object Structures
- Sequence Object Structures
- Buffer Object Structures
- Async Object Structures
- 使對象類型支持循環垃圾回收
- API 和 ABI 版本管理
- 分發 Python 模塊
- 關鍵術語
- 開源許可與協作
- 安裝工具
- 閱讀指南
- 我該如何...?
- ...為我的項目選擇一個名字?
- ...創建和分發二進制擴展?
- 安裝 Python 模塊
- 關鍵術語
- 基本使用
- 我應如何 ...?
- ... 在 Python 3.4 之前的 Python 版本中安裝 pip ?
- ... 只為當前用戶安裝軟件包?
- ... 安裝科學計算類 Python 軟件包?
- ... 使用并行安裝的多個 Python 版本?
- 常見的安裝問題
- 在 Linux 的系統 Python 版本上安裝
- 未安裝 pip
- 安裝二進制編譯擴展
- Python 常用指引
- 將 Python 2 代碼遷移到 Python 3
- 簡要說明
- 詳情
- 將擴展模塊移植到 Python 3
- 條件編譯
- 對象API的更改
- 模塊初始化和狀態
- CObject 替換為 Capsule
- 其他選項
- Curses Programming with Python
- What is curses?
- Starting and ending a curses application
- Windows and Pads
- Displaying Text
- User Input
- For More Information
- 實現描述器
- 摘要
- 定義和簡介
- 描述器協議
- 發起調用描述符
- 描述符示例
- Properties
- 函數和方法
- Static Methods and Class Methods
- 函數式編程指引
- 概述
- 迭代器
- 生成器表達式和列表推導式
- 生成器
- 內置函數
- itertools 模塊
- The functools module
- Small functions and the lambda expression
- Revision History and Acknowledgements
- 引用文獻
- 日志 HOWTO
- 日志基礎教程
- 進階日志教程
- 日志級別
- 有用的處理程序
- 記錄日志中引發的異常
- 使用任意對象作為消息
- 優化
- 日志操作手冊
- 在多個模塊中使用日志
- 在多線程中使用日志
- 使用多個日志處理器和多種格式化
- 在多個地方記錄日志
- 日志服務器配置示例
- 處理日志處理器的阻塞
- Sending and receiving logging events across a network
- Adding contextual information to your logging output
- Logging to a single file from multiple processes
- Using file rotation
- Use of alternative formatting styles
- Customizing LogRecord
- Subclassing QueueHandler - a ZeroMQ example
- Subclassing QueueListener - a ZeroMQ example
- An example dictionary-based configuration
- Using a rotator and namer to customize log rotation processing
- A more elaborate multiprocessing example
- Inserting a BOM into messages sent to a SysLogHandler
- Implementing structured logging
- Customizing handlers with dictConfig()
- Using particular formatting styles throughout your application
- Configuring filters with dictConfig()
- Customized exception formatting
- Speaking logging messages
- Buffering logging messages and outputting them conditionally
- Formatting times using UTC (GMT) via configuration
- Using a context manager for selective logging
- 正則表達式HOWTO
- 概述
- 簡單模式
- 使用正則表達式
- 更多模式能力
- 修改字符串
- 常見問題
- 反饋
- 套接字編程指南
- 套接字
- 創建套接字
- 使用一個套接字
- 斷開連接
- 非阻塞的套接字
- 排序指南
- 基本排序
- 關鍵函數
- Operator 模塊函數
- 升序和降序
- 排序穩定性和排序復雜度
- 使用裝飾-排序-去裝飾的舊方法
- 使用 cmp 參數的舊方法
- 其它
- Unicode 指南
- Unicode 概述
- Python's Unicode Support
- Reading and Writing Unicode Data
- Acknowledgements
- 如何使用urllib包獲取網絡資源
- 概述
- Fetching URLs
- 處理異常
- info and geturl
- Openers and Handlers
- Basic Authentication
- Proxies
- Sockets and Layers
- 腳注
- Argparse 教程
- 概念
- 基礎
- 位置參數介紹
- Introducing Optional arguments
- Combining Positional and Optional arguments
- Getting a little more advanced
- Conclusion
- ipaddress模塊介紹
- 創建 Address/Network/Interface 對象
- 審查 Address/Network/Interface 對象
- Network 作為 Address 列表
- 比較
- 將IP地址與其他模塊一起使用
- 實例創建失敗時獲取更多詳細信息
- Argument Clinic How-To
- The Goals Of Argument Clinic
- Basic Concepts And Usage
- Converting Your First Function
- Advanced Topics
- 使用 DTrace 和 SystemTap 檢測CPython
- Enabling the static markers
- Static DTrace probes
- Static SystemTap markers
- Available static markers
- SystemTap Tapsets
- 示例
- Python 常見問題
- Python常見問題
- 一般信息
- 現實世界中的 Python
- 編程常見問題
- 一般問題
- 核心語言
- 數字和字符串
- 性能
- 序列(元組/列表)
- 對象
- 模塊
- 設計和歷史常見問題
- 為什么Python使用縮進來分組語句?
- 為什么簡單的算術運算得到奇怪的結果?
- 為什么浮點計算不準確?
- 為什么Python字符串是不可變的?
- 為什么必須在方法定義和調用中顯式使用“self”?
- 為什么不能在表達式中賦值?
- 為什么Python對某些功能(例如list.index())使用方法來實現,而其他功能(例如len(List))使用函數實現?
- 為什么 join()是一個字符串方法而不是列表或元組方法?
- 異常有多快?
- 為什么Python中沒有switch或case語句?
- 難道不能在解釋器中模擬線程,而非得依賴特定于操作系統的線程實現嗎?
- 為什么lambda表達式不能包含語句?
- 可以將Python編譯為機器代碼,C或其他語言嗎?
- Python如何管理內存?
- 為什么CPython不使用更傳統的垃圾回收方案?
- CPython退出時為什么不釋放所有內存?
- 為什么有單獨的元組和列表數據類型?
- 列表是如何在CPython中實現的?
- 字典是如何在CPython中實現的?
- 為什么字典key必須是不可變的?
- 為什么 list.sort() 沒有返回排序列表?
- 如何在Python中指定和實施接口規范?
- 為什么沒有goto?
- 為什么原始字符串(r-strings)不能以反斜杠結尾?
- 為什么Python沒有屬性賦值的“with”語句?
- 為什么 if/while/def/class語句需要冒號?
- 為什么Python在列表和元組的末尾允許使用逗號?
- 代碼庫和插件 FAQ
- 通用的代碼庫問題
- 通用任務
- 線程相關
- 輸入輸出
- 網絡 / Internet 編程
- 數據庫
- 數學和數字
- 擴展/嵌入常見問題
- 可以使用C語言中創建自己的函數嗎?
- 可以使用C++語言中創建自己的函數嗎?
- C很難寫,有沒有其他選擇?
- 如何從C執行任意Python語句?
- 如何從C中評估任意Python表達式?
- 如何從Python對象中提取C的值?
- 如何使用Py_BuildValue()創建任意長度的元組?
- 如何從C調用對象的方法?
- 如何捕獲PyErr_Print()(或打印到stdout / stderr的任何內容)的輸出?
- 如何從C訪問用Python編寫的模塊?
- 如何從Python接口到C ++對象?
- 我使用Setup文件添加了一個模塊,為什么make失敗了?
- 如何調試擴展?
- 我想在Linux系統上編譯一個Python模塊,但是缺少一些文件。為什么?
- 如何區分“輸入不完整”和“輸入無效”?
- 如何找到未定義的g++符號__builtin_new或__pure_virtual?
- 能否創建一個對象類,其中部分方法在C中實現,而其他方法在Python中實現(例如通過繼承)?
- Python在Windows上的常見問題
- 我怎樣在Windows下運行一個Python程序?
- 我怎么讓 Python 腳本可執行?
- 為什么有時候 Python 程序會啟動緩慢?
- 我怎樣使用Python腳本制作可執行文件?
- *.pyd 文件和DLL文件相同嗎?
- 我怎樣將Python嵌入一個Windows程序?
- 如何讓編輯器不要在我的 Python 源代碼中插入 tab ?
- 如何在不阻塞的情況下檢查按鍵?
- 圖形用戶界面(GUI)常見問題
- 圖形界面常見問題
- Python 是否有平臺無關的圖形界面工具包?
- 有哪些Python的GUI工具是某個平臺專用的?
- 有關Tkinter的問題
- “為什么我的電腦上安裝了 Python ?”
- 什么是Python?
- 為什么我的電腦上安裝了 Python ?
- 我能刪除 Python 嗎?
- 術語對照表
- 文檔說明
- Python 文檔貢獻者
- 解決 Bug
- 文檔錯誤
- 使用 Python 的錯誤追蹤系統
- 開始為 Python 貢獻您的知識
- 版權
- 歷史和許可證
- 軟件歷史
- 訪問Python或以其他方式使用Python的條款和條件
- Python 3.7.3 的 PSF 許可協議
- Python 2.0 的 BeOpen.com 許可協議
- Python 1.6.1 的 CNRI 許可協議
- Python 0.9.0 至 1.2 的 CWI 許可協議
- 集成軟件的許可和認可
- Mersenne Twister
- 套接字
- Asynchronous socket services
- Cookie management
- Execution tracing
- UUencode and UUdecode functions
- XML Remote Procedure Calls
- test_epoll
- Select kqueue
- SipHash24
- strtod and dtoa
- OpenSSL
- expat
- libffi
- zlib
- cfuhash
- libmpdec