### 導航
- [索引](../genindex.xhtml "總目錄")
- [模塊](../py-modindex.xhtml "Python 模塊索引") |
- [下一頁](gcsupport.xhtml "使對象類型支持循環垃圾回收") |
- [上一頁](structures.xhtml "Common Object Structures") |
- 
- [Python](https://www.python.org/) ?
- zh\_CN 3.7.3 [文檔](../index.xhtml) ?
- [Python/C API 參考手冊](index.xhtml) ?
- [對象實現支持](objimpl.xhtml) ?
- $('.inline-search').show(0); |
# Type 對象
Perhaps one of the most important structures of the Python object system is the structure that defines a new type: the [`PyTypeObject`](type.xhtml#c.PyTypeObject "PyTypeObject") structure. Type objects can be handled using any of the `PyObject_*()` or `PyType_*()` functions, but do not offer much that's interesting to most Python applications. These objects are fundamental to how objects behave, so they are very important to the interpreter itself and to any extension module that implements new types.
Type objects are fairly large compared to most of the standard types. The reason for the size is that each type object stores a large number of values, mostly C function pointers, each of which implements a small part of the type's functionality. The fields of the type object are examined in detail in this section. The fields will be described in the order in which they occur in the structure.
Typedefs: unaryfunc, binaryfunc, ternaryfunc, inquiry, intargfunc, intintargfunc, intobjargproc, intintobjargproc, objobjargproc, destructor, freefunc, printfunc, getattrfunc, getattrofunc, setattrfunc, setattrofunc, reprfunc, hashfunc
The structure definition for [`PyTypeObject`](type.xhtml#c.PyTypeObject "PyTypeObject") can be found in `Include/object.h`. For convenience of reference, this repeats the definition found there:
```
typedef struct _typeobject {
PyObject_VAR_HEAD
const char *tp_name; /* For printing, in format "<module>.<name>" */
Py_ssize_t tp_basicsize, tp_itemsize; /* For allocation */
/* Methods to implement standard operations */
destructor tp_dealloc;
printfunc tp_print;
getattrfunc tp_getattr;
setattrfunc tp_setattr;
PyAsyncMethods *tp_as_async; /* formerly known as tp_compare (Python 2)
or tp_reserved (Python 3) */
reprfunc tp_repr;
/* Method suites for standard classes */
PyNumberMethods *tp_as_number;
PySequenceMethods *tp_as_sequence;
PyMappingMethods *tp_as_mapping;
/* More standard operations (here for binary compatibility) */
hashfunc tp_hash;
ternaryfunc tp_call;
reprfunc tp_str;
getattrofunc tp_getattro;
setattrofunc tp_setattro;
/* Functions to access object as input/output buffer */
PyBufferProcs *tp_as_buffer;
/* Flags to define presence of optional/expanded features */
unsigned long tp_flags;
const char *tp_doc; /* Documentation string */
/* call function for all accessible objects */
traverseproc tp_traverse;
/* delete references to contained objects */
inquiry tp_clear;
/* rich comparisons */
richcmpfunc tp_richcompare;
/* weak reference enabler */
Py_ssize_t tp_weaklistoffset;
/* Iterators */
getiterfunc tp_iter;
iternextfunc tp_iternext;
/* Attribute descriptor and subclassing stuff */
struct PyMethodDef *tp_methods;
struct PyMemberDef *tp_members;
struct PyGetSetDef *tp_getset;
struct _typeobject *tp_base;
PyObject *tp_dict;
descrgetfunc tp_descr_get;
descrsetfunc tp_descr_set;
Py_ssize_t tp_dictoffset;
initproc tp_init;
allocfunc tp_alloc;
newfunc tp_new;
freefunc tp_free; /* Low-level free-memory routine */
inquiry tp_is_gc; /* For PyObject_IS_GC */
PyObject *tp_bases;
PyObject *tp_mro; /* method resolution order */
PyObject *tp_cache;
PyObject *tp_subclasses;
PyObject *tp_weaklist;
destructor tp_del;
/* Type attribute cache version tag. Added in version 2.6 */
unsigned int tp_version_tag;
destructor tp_finalize;
} PyTypeObject;
```
The type object structure extends the [`PyVarObject`](structures.xhtml#c.PyVarObject "PyVarObject") structure. The `ob_size` field is used for dynamic types (created by `type_new()`, usually called from a class statement). Note that [`PyType_Type`](type.xhtml#c.PyType_Type "PyType_Type") (the metatype) initializes [`tp_itemsize`](#c.PyTypeObject.tp_itemsize "PyTypeObject.tp_itemsize"), which means that its instances (i.e. type objects) *must* have the `ob_size` field.
[PyObject](structures.xhtml#c.PyObject "PyObject")\* `PyObject._ob_next`[PyObject](structures.xhtml#c.PyObject "PyObject")\* `PyObject._ob_prev`These fields are only present when the macro `Py_TRACE_REFS` is defined. Their initialization to *NULL* is taken care of by the `PyObject_HEAD_INIT`macro. For statically allocated objects, these fields always remain *NULL*. For dynamically allocated objects, these two fields are used to link the object into a doubly-linked list of *all* live objects on the heap. This could be used for various debugging purposes; currently the only use is to print the objects that are still alive at the end of a run when the environment variable [`PYTHONDUMPREFS`](../using/cmdline.xhtml#envvar-PYTHONDUMPREFS) is set.
These fields are not inherited by subtypes.
Py\_ssize\_t `PyObject.ob_refcnt`This is the type object's reference count, initialized to `1` by the `PyObject_HEAD_INIT` macro. Note that for statically allocated type objects, the type's instances (objects whose `ob_type` points back to the type) do *not* count as references. But for dynamically allocated type objects, the instances *do* count as references.
This field is not inherited by subtypes.
[PyTypeObject](type.xhtml#c.PyTypeObject "PyTypeObject")\* `PyObject.ob_type`This is the type's type, in other words its metatype. It is initialized by the argument to the `PyObject_HEAD_INIT` macro, and its value should normally be `&PyType_Type`. However, for dynamically loadable extension modules that must be usable on Windows (at least), the compiler complains that this is not a valid initializer. Therefore, the convention is to pass *NULL* to the `PyObject_HEAD_INIT` macro and to initialize this field explicitly at the start of the module's initialization function, before doing anything else. This is typically done like this:
```
Foo_Type.ob_type = &PyType_Type;
```
This should be done before any instances of the type are created. [`PyType_Ready()`](type.xhtml#c.PyType_Ready "PyType_Ready") checks if `ob_type` is *NULL*, and if so, initializes it to the `ob_type` field of the base class. [`PyType_Ready()`](type.xhtml#c.PyType_Ready "PyType_Ready") will not change this field if it is non-zero.
This field is inherited by subtypes.
Py\_ssize\_t `PyVarObject.ob_size`For statically allocated type objects, this should be initialized to zero. For dynamically allocated type objects, this field has a special internal meaning.
This field is not inherited by subtypes.
const char\* `PyTypeObject.tp_name`Pointer to a NUL-terminated string containing the name of the type. For types that are accessible as module globals, the string should be the full module name, followed by a dot, followed by the type name; for built-in types, it should be just the type name. If the module is a submodule of a package, the full package name is part of the full module name. For example, a type named `T` defined in module `M` in subpackage `Q` in package `P`should have the [`tp_name`](#c.PyTypeObject.tp_name "PyTypeObject.tp_name") initializer `"P.Q.M.T"`.
For dynamically allocated type objects, this should just be the type name, and the module name explicitly stored in the type dict as the value for key `'__module__'`.
For statically allocated type objects, the tp\_name field should contain a dot. Everything before the last dot is made accessible as the `__module__`attribute, and everything after the last dot is made accessible as the [`__name__`](../library/stdtypes.xhtml#definition.__name__ "definition.__name__") attribute.
If no dot is present, the entire [`tp_name`](#c.PyTypeObject.tp_name "PyTypeObject.tp_name") field is made accessible as the [`__name__`](../library/stdtypes.xhtml#definition.__name__ "definition.__name__") attribute, and the `__module__` attribute is undefined (unless explicitly set in the dictionary, as explained above). This means your type will be impossible to pickle. Additionally, it will not be listed in module documentations created with pydoc.
This field is not inherited by subtypes.
Py\_ssize\_t `PyTypeObject.tp_basicsize`Py\_ssize\_t `PyTypeObject.tp_itemsize`These fields allow calculating the size in bytes of instances of the type.
There are two kinds of types: types with fixed-length instances have a zero [`tp_itemsize`](#c.PyTypeObject.tp_itemsize "PyTypeObject.tp_itemsize") field, types with variable-length instances have a non-zero [`tp_itemsize`](#c.PyTypeObject.tp_itemsize "PyTypeObject.tp_itemsize") field. For a type with fixed-length instances, all instances have the same size, given in [`tp_basicsize`](#c.PyTypeObject.tp_basicsize "PyTypeObject.tp_basicsize").
For a type with variable-length instances, the instances must have an `ob_size` field, and the instance size is [`tp_basicsize`](#c.PyTypeObject.tp_basicsize "PyTypeObject.tp_basicsize") plus N times [`tp_itemsize`](#c.PyTypeObject.tp_itemsize "PyTypeObject.tp_itemsize"), where N is the "length" of the object. The value of N is typically stored in the instance's `ob_size` field. There are exceptions: for example, ints use a negative `ob_size` to indicate a negative number, and N is `abs(ob_size)` there. Also, the presence of an `ob_size` field in the instance layout doesn't mean that the instance structure is variable-length (for example, the structure for the list type has fixed-length instances, yet those instances have a meaningful `ob_size`field).
The basic size includes the fields in the instance declared by the macro [`PyObject_HEAD`](structures.xhtml#c.PyObject_HEAD "PyObject_HEAD") or [`PyObject_VAR_HEAD`](structures.xhtml#c.PyObject_VAR_HEAD "PyObject_VAR_HEAD") (whichever is used to declare the instance struct) and this in turn includes the `_ob_prev` and `_ob_next` fields if they are present. This means that the only correct way to get an initializer for the [`tp_basicsize`](#c.PyTypeObject.tp_basicsize "PyTypeObject.tp_basicsize") is to use the `sizeof` operator on the struct used to declare the instance layout. The basic size does not include the GC header size.
These fields are inherited separately by subtypes. If the base type has a non-zero [`tp_itemsize`](#c.PyTypeObject.tp_itemsize "PyTypeObject.tp_itemsize"), it is generally not safe to set [`tp_itemsize`](#c.PyTypeObject.tp_itemsize "PyTypeObject.tp_itemsize") to a different non-zero value in a subtype (though this depends on the implementation of the base type).
A note about alignment: if the variable items require a particular alignment, this should be taken care of by the value of [`tp_basicsize`](#c.PyTypeObject.tp_basicsize "PyTypeObject.tp_basicsize"). Example: suppose a type implements an array of `double`. [`tp_itemsize`](#c.PyTypeObject.tp_itemsize "PyTypeObject.tp_itemsize") is `sizeof(double)`. It is the programmer's responsibility that [`tp_basicsize`](#c.PyTypeObject.tp_basicsize "PyTypeObject.tp_basicsize") is a multiple of `sizeof(double)` (assuming this is the alignment requirement for `double`).
destructor `PyTypeObject.tp_dealloc`A pointer to the instance destructor function. This function must be defined unless the type guarantees that its instances will never be deallocated (as is the case for the singletons `None` and `Ellipsis`).
The destructor function is called by the [`Py_DECREF()`](refcounting.xhtml#c.Py_DECREF "Py_DECREF") and [`Py_XDECREF()`](refcounting.xhtml#c.Py_XDECREF "Py_XDECREF") macros when the new reference count is zero. At this point, the instance is still in existence, but there are no references to it. The destructor function should free all references which the instance owns, free all memory buffers owned by the instance (using the freeing function corresponding to the allocation function used to allocate the buffer), and finally (as its last action) call the type's [`tp_free`](#c.PyTypeObject.tp_free "PyTypeObject.tp_free") function. If the type is not subtypable (doesn't have the [`Py_TPFLAGS_BASETYPE`](#Py_TPFLAGS_BASETYPE "Py_TPFLAGS_BASETYPE") flag bit set), it is permissible to call the object deallocator directly instead of via [`tp_free`](#c.PyTypeObject.tp_free "PyTypeObject.tp_free"). The object deallocator should be the one used to allocate the instance; this is normally [`PyObject_Del()`](allocation.xhtml#c.PyObject_Del "PyObject_Del") if the instance was allocated using [`PyObject_New()`](allocation.xhtml#c.PyObject_New "PyObject_New") or `PyObject_VarNew()`, or [`PyObject_GC_Del()`](gcsupport.xhtml#c.PyObject_GC_Del "PyObject_GC_Del") if the instance was allocated using [`PyObject_GC_New()`](gcsupport.xhtml#c.PyObject_GC_New "PyObject_GC_New") or [`PyObject_GC_NewVar()`](gcsupport.xhtml#c.PyObject_GC_NewVar "PyObject_GC_NewVar").
This field is inherited by subtypes.
printfunc `PyTypeObject.tp_print`Reserved slot, formerly used for print formatting in Python 2.x.
getattrfunc `PyTypeObject.tp_getattr`An optional pointer to the get-attribute-string function.
This field is deprecated. When it is defined, it should point to a function that acts the same as the [`tp_getattro`](#c.PyTypeObject.tp_getattro "PyTypeObject.tp_getattro") function, but taking a C string instead of a Python string object to give the attribute name. The signature is
```
PyObject * tp_getattr(PyObject *o, char *attr_name);
```
This field is inherited by subtypes together with [`tp_getattro`](#c.PyTypeObject.tp_getattro "PyTypeObject.tp_getattro"): a subtype inherits both [`tp_getattr`](#c.PyTypeObject.tp_getattr "PyTypeObject.tp_getattr") and [`tp_getattro`](#c.PyTypeObject.tp_getattro "PyTypeObject.tp_getattro") from its base type when the subtype's [`tp_getattr`](#c.PyTypeObject.tp_getattr "PyTypeObject.tp_getattr") and [`tp_getattro`](#c.PyTypeObject.tp_getattro "PyTypeObject.tp_getattro") are both *NULL*.
setattrfunc `PyTypeObject.tp_setattr`An optional pointer to the function for setting and deleting attributes.
This field is deprecated. When it is defined, it should point to a function that acts the same as the [`tp_setattro`](#c.PyTypeObject.tp_setattro "PyTypeObject.tp_setattro") function, but taking a C string instead of a Python string object to give the attribute name. The signature is
```
PyObject * tp_setattr(PyObject *o, char *attr_name, PyObject *v);
```
The *v* argument is set to *NULL* to delete the attribute. This field is inherited by subtypes together with [`tp_setattro`](#c.PyTypeObject.tp_setattro "PyTypeObject.tp_setattro"): a subtype inherits both [`tp_setattr`](#c.PyTypeObject.tp_setattr "PyTypeObject.tp_setattr") and [`tp_setattro`](#c.PyTypeObject.tp_setattro "PyTypeObject.tp_setattro") from its base type when the subtype's [`tp_setattr`](#c.PyTypeObject.tp_setattr "PyTypeObject.tp_setattr") and [`tp_setattro`](#c.PyTypeObject.tp_setattro "PyTypeObject.tp_setattro") are both *NULL*.
[PyAsyncMethods](#c.PyAsyncMethods "PyAsyncMethods")\* `tp_as_async`Pointer to an additional structure that contains fields relevant only to objects which implement [awaitable](../glossary.xhtml#term-awaitable) and [asynchronous iterator](../glossary.xhtml#term-asynchronous-iterator)protocols at the C-level. See [Async Object Structures](#async-structs) for details.
3\.5 新版功能: Formerly known as `tp_compare` and `tp_reserved`.
reprfunc `PyTypeObject.tp_repr`An optional pointer to a function that implements the built-in function [`repr()`](../library/functions.xhtml#repr "repr").
The signature is the same as for [`PyObject_Repr()`](object.xhtml#c.PyObject_Repr "PyObject_Repr"); it must return a string or a Unicode object. Ideally, this function should return a string that, when passed to [`eval()`](../library/functions.xhtml#eval "eval"), given a suitable environment, returns an object with the same value. If this is not feasible, it should return a string starting with `'<'` and ending with `'>'` from which both the type and the value of the object can be deduced.
When this field is not set, a string of the form `<%s object at %p>` is returned, where `%s` is replaced by the type name, and `%p` by the object's memory address.
This field is inherited by subtypes.
[PyNumberMethods](#c.PyNumberMethods "PyNumberMethods")\* `tp_as_number`Pointer to an additional structure that contains fields relevant only to objects which implement the number protocol. These fields are documented in [Number Object Structures](#number-structs).
The `tp_as_number` field is not inherited, but the contained fields are inherited individually.
[PySequenceMethods](#c.PySequenceMethods "PySequenceMethods")\* `tp_as_sequence`Pointer to an additional structure that contains fields relevant only to objects which implement the sequence protocol. These fields are documented in [Sequence Object Structures](#sequence-structs).
The `tp_as_sequence` field is not inherited, but the contained fields are inherited individually.
[PyMappingMethods](#c.PyMappingMethods "PyMappingMethods")\* `tp_as_mapping`Pointer to an additional structure that contains fields relevant only to objects which implement the mapping protocol. These fields are documented in [Mapping Object Structures](#mapping-structs).
The `tp_as_mapping` field is not inherited, but the contained fields are inherited individually.
hashfunc `PyTypeObject.tp_hash`An optional pointer to a function that implements the built-in function [`hash()`](../library/functions.xhtml#hash "hash").
The signature is the same as for [`PyObject_Hash()`](object.xhtml#c.PyObject_Hash "PyObject_Hash"); it must return a value of the type Py\_hash\_t. The value `-1` should not be returned as a normal return value; when an error occurs during the computation of the hash value, the function should set an exception and return `-1`.
This field can be set explicitly to [`PyObject_HashNotImplemented()`](object.xhtml#c.PyObject_HashNotImplemented "PyObject_HashNotImplemented") to block inheritance of the hash method from a parent type. This is interpreted as the equivalent of `__hash__ = None` at the Python level, causing `isinstance(o, collections.Hashable)` to correctly return `False`. Note that the converse is also true - setting `__hash__ = None` on a class at the Python level will result in the `tp_hash` slot being set to [`PyObject_HashNotImplemented()`](object.xhtml#c.PyObject_HashNotImplemented "PyObject_HashNotImplemented").
When this field is not set, an attempt to take the hash of the object raises [`TypeError`](../library/exceptions.xhtml#TypeError "TypeError").
This field is inherited by subtypes together with [`tp_richcompare`](#c.PyTypeObject.tp_richcompare "PyTypeObject.tp_richcompare"): a subtype inherits both of [`tp_richcompare`](#c.PyTypeObject.tp_richcompare "PyTypeObject.tp_richcompare") and [`tp_hash`](#c.PyTypeObject.tp_hash "PyTypeObject.tp_hash"), when the subtype's [`tp_richcompare`](#c.PyTypeObject.tp_richcompare "PyTypeObject.tp_richcompare") and [`tp_hash`](#c.PyTypeObject.tp_hash "PyTypeObject.tp_hash") are both *NULL*.
ternaryfunc `PyTypeObject.tp_call`An optional pointer to a function that implements calling the object. This should be *NULL* if the object is not callable. The signature is the same as for [`PyObject_Call()`](object.xhtml#c.PyObject_Call "PyObject_Call").
This field is inherited by subtypes.
reprfunc `PyTypeObject.tp_str`An optional pointer to a function that implements the built-in operation [`str()`](../library/stdtypes.xhtml#str "str"). (Note that [`str`](../library/stdtypes.xhtml#str "str") is a type now, and [`str()`](../library/stdtypes.xhtml#str "str") calls the constructor for that type. This constructor calls [`PyObject_Str()`](object.xhtml#c.PyObject_Str "PyObject_Str") to do the actual work, and [`PyObject_Str()`](object.xhtml#c.PyObject_Str "PyObject_Str") will call this handler.)
The signature is the same as for [`PyObject_Str()`](object.xhtml#c.PyObject_Str "PyObject_Str"); it must return a string or a Unicode object. This function should return a "friendly" string representation of the object, as this is the representation that will be used, among other things, by the [`print()`](../library/functions.xhtml#print "print") function.
When this field is not set, [`PyObject_Repr()`](object.xhtml#c.PyObject_Repr "PyObject_Repr") is called to return a string representation.
This field is inherited by subtypes.
getattrofunc `PyTypeObject.tp_getattro`An optional pointer to the get-attribute function.
The signature is the same as for [`PyObject_GetAttr()`](object.xhtml#c.PyObject_GetAttr "PyObject_GetAttr"). It is usually convenient to set this field to [`PyObject_GenericGetAttr()`](object.xhtml#c.PyObject_GenericGetAttr "PyObject_GenericGetAttr"), which implements the normal way of looking for object attributes.
This field is inherited by subtypes together with [`tp_getattr`](#c.PyTypeObject.tp_getattr "PyTypeObject.tp_getattr"): a subtype inherits both [`tp_getattr`](#c.PyTypeObject.tp_getattr "PyTypeObject.tp_getattr") and [`tp_getattro`](#c.PyTypeObject.tp_getattro "PyTypeObject.tp_getattro") from its base type when the subtype's [`tp_getattr`](#c.PyTypeObject.tp_getattr "PyTypeObject.tp_getattr") and [`tp_getattro`](#c.PyTypeObject.tp_getattro "PyTypeObject.tp_getattro") are both *NULL*.
setattrofunc `PyTypeObject.tp_setattro`An optional pointer to the function for setting and deleting attributes.
The signature is the same as for [`PyObject_SetAttr()`](object.xhtml#c.PyObject_SetAttr "PyObject_SetAttr"), but setting *v* to *NULL* to delete an attribute must be supported. It is usually convenient to set this field to [`PyObject_GenericSetAttr()`](object.xhtml#c.PyObject_GenericSetAttr "PyObject_GenericSetAttr"), which implements the normal way of setting object attributes.
This field is inherited by subtypes together with [`tp_setattr`](#c.PyTypeObject.tp_setattr "PyTypeObject.tp_setattr"): a subtype inherits both [`tp_setattr`](#c.PyTypeObject.tp_setattr "PyTypeObject.tp_setattr") and [`tp_setattro`](#c.PyTypeObject.tp_setattro "PyTypeObject.tp_setattro") from its base type when the subtype's [`tp_setattr`](#c.PyTypeObject.tp_setattr "PyTypeObject.tp_setattr") and [`tp_setattro`](#c.PyTypeObject.tp_setattro "PyTypeObject.tp_setattro") are both *NULL*.
[PyBufferProcs](#c.PyBufferProcs "PyBufferProcs")\* `PyTypeObject.tp_as_buffer`Pointer to an additional structure that contains fields relevant only to objects which implement the buffer interface. These fields are documented in [Buffer Object Structures](#buffer-structs).
The [`tp_as_buffer`](#c.PyTypeObject.tp_as_buffer "PyTypeObject.tp_as_buffer") field is not inherited, but the contained fields are inherited individually.
unsigned long `PyTypeObject.tp_flags`This field is a bit mask of various flags. Some flags indicate variant semantics for certain situations; others are used to indicate that certain fields in the type object (or in the extension structures referenced via `tp_as_number`, `tp_as_sequence`, `tp_as_mapping`, and [`tp_as_buffer`](#c.PyTypeObject.tp_as_buffer "PyTypeObject.tp_as_buffer")) that were historically not always present are valid; if such a flag bit is clear, the type fields it guards must not be accessed and must be considered to have a zero or *NULL* value instead.
Inheritance of this field is complicated. Most flag bits are inherited individually, i.e. if the base type has a flag bit set, the subtype inherits this flag bit. The flag bits that pertain to extension structures are strictly inherited if the extension structure is inherited, i.e. the base type's value of the flag bit is copied into the subtype together with a pointer to the extension structure. The [`Py_TPFLAGS_HAVE_GC`](#Py_TPFLAGS_HAVE_GC "Py_TPFLAGS_HAVE_GC") flag bit is inherited together with the [`tp_traverse`](#c.PyTypeObject.tp_traverse "PyTypeObject.tp_traverse") and [`tp_clear`](#c.PyTypeObject.tp_clear "PyTypeObject.tp_clear") fields, i.e. if the [`Py_TPFLAGS_HAVE_GC`](#Py_TPFLAGS_HAVE_GC "Py_TPFLAGS_HAVE_GC") flag bit is clear in the subtype and the [`tp_traverse`](#c.PyTypeObject.tp_traverse "PyTypeObject.tp_traverse") and [`tp_clear`](#c.PyTypeObject.tp_clear "PyTypeObject.tp_clear") fields in the subtype exist and have *NULL* values.
The following bit masks are currently defined; these can be ORed together using the `|` operator to form the value of the [`tp_flags`](#c.PyTypeObject.tp_flags "PyTypeObject.tp_flags") field. The macro [`PyType_HasFeature()`](type.xhtml#c.PyType_HasFeature "PyType_HasFeature") takes a type and a flags value, *tp* and *f*, and checks whether `tp->tp_flags & f` is non-zero.
`Py_TPFLAGS_HEAPTYPE`This bit is set when the type object itself is allocated on the heap. In this case, the `ob_type` field of its instances is considered a reference to the type, and the type object is INCREF'ed when a new instance is created, and DECREF'ed when an instance is destroyed (this does not apply to instances of subtypes; only the type referenced by the instance's ob\_type gets INCREF'ed or DECREF'ed).
`Py_TPFLAGS_BASETYPE`This bit is set when the type can be used as the base type of another type. If this bit is clear, the type cannot be subtyped (similar to a "final" class in Java).
`Py_TPFLAGS_READY`This bit is set when the type object has been fully initialized by [`PyType_Ready()`](type.xhtml#c.PyType_Ready "PyType_Ready").
`Py_TPFLAGS_READYING`This bit is set while [`PyType_Ready()`](type.xhtml#c.PyType_Ready "PyType_Ready") is in the process of initializing the type object.
`Py_TPFLAGS_HAVE_GC`This bit is set when the object supports garbage collection. If this bit is set, instances must be created using [`PyObject_GC_New()`](gcsupport.xhtml#c.PyObject_GC_New "PyObject_GC_New") and destroyed using [`PyObject_GC_Del()`](gcsupport.xhtml#c.PyObject_GC_Del "PyObject_GC_Del"). More information in section [使對象類型支持循環垃圾回收](gcsupport.xhtml#supporting-cycle-detection). This bit also implies that the GC-related fields [`tp_traverse`](#c.PyTypeObject.tp_traverse "PyTypeObject.tp_traverse") and [`tp_clear`](#c.PyTypeObject.tp_clear "PyTypeObject.tp_clear") are present in the type object.
`Py_TPFLAGS_DEFAULT`This is a bitmask of all the bits that pertain to the existence of certain fields in the type object and its extension structures. Currently, it includes the following bits: `Py_TPFLAGS_HAVE_STACKLESS_EXTENSION`, `Py_TPFLAGS_HAVE_VERSION_TAG`.
`Py_TPFLAGS_LONG_SUBCLASS``Py_TPFLAGS_LIST_SUBCLASS``Py_TPFLAGS_TUPLE_SUBCLASS``Py_TPFLAGS_BYTES_SUBCLASS``Py_TPFLAGS_UNICODE_SUBCLASS``Py_TPFLAGS_DICT_SUBCLASS``Py_TPFLAGS_BASE_EXC_SUBCLASS``Py_TPFLAGS_TYPE_SUBCLASS`These flags are used by functions such as [`PyLong_Check()`](long.xhtml#c.PyLong_Check "PyLong_Check") to quickly determine if a type is a subclass of a built-in type; such specific checks are faster than a generic check, like [`PyObject_IsInstance()`](object.xhtml#c.PyObject_IsInstance "PyObject_IsInstance"). Custom types that inherit from built-ins should have their [`tp_flags`](#c.PyTypeObject.tp_flags "PyTypeObject.tp_flags")set appropriately, or the code that interacts with such types will behave differently depending on what kind of check is used.
`Py_TPFLAGS_HAVE_FINALIZE`This bit is set when the [`tp_finalize`](#c.PyTypeObject.tp_finalize "PyTypeObject.tp_finalize") slot is present in the type structure.
3\.4 新版功能.
const char\* `PyTypeObject.tp_doc`An optional pointer to a NUL-terminated C string giving the docstring for this type object. This is exposed as the `__doc__` attribute on the type and instances of the type.
This field is *not* inherited by subtypes.
[traverseproc](gcsupport.xhtml#c.traverseproc "traverseproc")`PyTypeObject.tp_traverse`An optional pointer to a traversal function for the garbage collector. This is only used if the [`Py_TPFLAGS_HAVE_GC`](#Py_TPFLAGS_HAVE_GC "Py_TPFLAGS_HAVE_GC") flag bit is set. More information about Python's garbage collection scheme can be found in section [使對象類型支持循環垃圾回收](gcsupport.xhtml#supporting-cycle-detection).
The [`tp_traverse`](#c.PyTypeObject.tp_traverse "PyTypeObject.tp_traverse") pointer is used by the garbage collector to detect reference cycles. A typical implementation of a [`tp_traverse`](#c.PyTypeObject.tp_traverse "PyTypeObject.tp_traverse") function simply calls [`Py_VISIT()`](gcsupport.xhtml#c.Py_VISIT "Py_VISIT") on each of the instance's members that are Python objects. For example, this is function `local_traverse()` from the [`_thread`](../library/_thread.xhtml#module-_thread "_thread: Low-level threading API.") extension module:
```
static int
local_traverse(localobject *self, visitproc visit, void *arg)
{
Py_VISIT(self->args);
Py_VISIT(self->kw);
Py_VISIT(self->dict);
return 0;
}
```
Note that [`Py_VISIT()`](gcsupport.xhtml#c.Py_VISIT "Py_VISIT") is called only on those members that can participate in reference cycles. Although there is also a `self->key` member, it can only be *NULL* or a Python string and therefore cannot be part of a reference cycle.
On the other hand, even if you know a member can never be part of a cycle, as a debugging aid you may want to visit it anyway just so the [`gc`](../library/gc.xhtml#module-gc "gc: Interface to the cycle-detecting garbage collector.") module's [`get_referents()`](../library/gc.xhtml#gc.get_referents "gc.get_referents") function will include it.
Note that [`Py_VISIT()`](gcsupport.xhtml#c.Py_VISIT "Py_VISIT") requires the *visit* and *arg* parameters to `local_traverse()` to have these specific names; don't name them just anything.
This field is inherited by subtypes together with [`tp_clear`](#c.PyTypeObject.tp_clear "PyTypeObject.tp_clear") and the [`Py_TPFLAGS_HAVE_GC`](#Py_TPFLAGS_HAVE_GC "Py_TPFLAGS_HAVE_GC") flag bit: the flag bit, [`tp_traverse`](#c.PyTypeObject.tp_traverse "PyTypeObject.tp_traverse"), and [`tp_clear`](#c.PyTypeObject.tp_clear "PyTypeObject.tp_clear") are all inherited from the base type if they are all zero in the subtype.
[inquiry](gcsupport.xhtml#c.inquiry "inquiry")`PyTypeObject.tp_clear`An optional pointer to a clear function for the garbage collector. This is only used if the [`Py_TPFLAGS_HAVE_GC`](#Py_TPFLAGS_HAVE_GC "Py_TPFLAGS_HAVE_GC") flag bit is set.
The [`tp_clear`](#c.PyTypeObject.tp_clear "PyTypeObject.tp_clear") member function is used to break reference cycles in cyclic garbage detected by the garbage collector. Taken together, all [`tp_clear`](#c.PyTypeObject.tp_clear "PyTypeObject.tp_clear")functions in the system must combine to break all reference cycles. This is subtle, and if in any doubt supply a [`tp_clear`](#c.PyTypeObject.tp_clear "PyTypeObject.tp_clear") function. For example, the tuple type does not implement a [`tp_clear`](#c.PyTypeObject.tp_clear "PyTypeObject.tp_clear") function, because it's possible to prove that no reference cycle can be composed entirely of tuples. Therefore the [`tp_clear`](#c.PyTypeObject.tp_clear "PyTypeObject.tp_clear") functions of other types must be sufficient to break any cycle containing a tuple. This isn't immediately obvious, and there's rarely a good reason to avoid implementing [`tp_clear`](#c.PyTypeObject.tp_clear "PyTypeObject.tp_clear").
Implementations of [`tp_clear`](#c.PyTypeObject.tp_clear "PyTypeObject.tp_clear") should drop the instance's references to those of its members that may be Python objects, and set its pointers to those members to *NULL*, as in the following example:
```
static int
local_clear(localobject *self)
{
Py_CLEAR(self->key);
Py_CLEAR(self->args);
Py_CLEAR(self->kw);
Py_CLEAR(self->dict);
return 0;
}
```
The [`Py_CLEAR()`](refcounting.xhtml#c.Py_CLEAR "Py_CLEAR") macro should be used, because clearing references is delicate: the reference to the contained object must not be decremented until after the pointer to the contained object is set to *NULL*. This is because decrementing the reference count may cause the contained object to become trash, triggering a chain of reclamation activity that may include invoking arbitrary Python code (due to finalizers, or weakref callbacks, associated with the contained object). If it's possible for such code to reference *self* again, it's important that the pointer to the contained object be *NULL* at that time, so that *self* knows the contained object can no longer be used. The [`Py_CLEAR()`](refcounting.xhtml#c.Py_CLEAR "Py_CLEAR") macro performs the operations in a safe order.
Because the goal of [`tp_clear`](#c.PyTypeObject.tp_clear "PyTypeObject.tp_clear") functions is to break reference cycles, it's not necessary to clear contained objects like Python strings or Python integers, which can't participate in reference cycles. On the other hand, it may be convenient to clear all contained Python objects, and write the type's [`tp_dealloc`](#c.PyTypeObject.tp_dealloc "PyTypeObject.tp_dealloc") function to invoke [`tp_clear`](#c.PyTypeObject.tp_clear "PyTypeObject.tp_clear").
More information about Python's garbage collection scheme can be found in section [使對象類型支持循環垃圾回收](gcsupport.xhtml#supporting-cycle-detection).
This field is inherited by subtypes together with [`tp_traverse`](#c.PyTypeObject.tp_traverse "PyTypeObject.tp_traverse") and the [`Py_TPFLAGS_HAVE_GC`](#Py_TPFLAGS_HAVE_GC "Py_TPFLAGS_HAVE_GC") flag bit: the flag bit, [`tp_traverse`](#c.PyTypeObject.tp_traverse "PyTypeObject.tp_traverse"), and [`tp_clear`](#c.PyTypeObject.tp_clear "PyTypeObject.tp_clear") are all inherited from the base type if they are all zero in the subtype.
richcmpfunc `PyTypeObject.tp_richcompare`An optional pointer to the rich comparison function, whose signature is `PyObject *tp_richcompare(PyObject *a, PyObject *b, int op)`. The first parameter is guaranteed to be an instance of the type that is defined by [`PyTypeObject`](type.xhtml#c.PyTypeObject "PyTypeObject").
The function should return the result of the comparison (usually `Py_True`or `Py_False`). If the comparison is undefined, it must return `Py_NotImplemented`, if another error occurred it must return `NULL` and set an exception condition.
注解
If you want to implement a type for which only a limited set of comparisons makes sense (e.g. `==` and `!=`, but not `<` and friends), directly raise [`TypeError`](../library/exceptions.xhtml#TypeError "TypeError") in the rich comparison function.
This field is inherited by subtypes together with [`tp_hash`](#c.PyTypeObject.tp_hash "PyTypeObject.tp_hash"): a subtype inherits [`tp_richcompare`](#c.PyTypeObject.tp_richcompare "PyTypeObject.tp_richcompare") and [`tp_hash`](#c.PyTypeObject.tp_hash "PyTypeObject.tp_hash") when the subtype's [`tp_richcompare`](#c.PyTypeObject.tp_richcompare "PyTypeObject.tp_richcompare") and [`tp_hash`](#c.PyTypeObject.tp_hash "PyTypeObject.tp_hash") are both *NULL*.
The following constants are defined to be used as the third argument for [`tp_richcompare`](#c.PyTypeObject.tp_richcompare "PyTypeObject.tp_richcompare") and for [`PyObject_RichCompare()`](object.xhtml#c.PyObject_RichCompare "PyObject_RichCompare"):
常數
Comparison
`Py_LT`
`<`
`Py_LE`
`<=`
`Py_EQ`
`==`
`Py_NE`
`!=`
`Py_GT`
`>`
`Py_GE`
`>=`
The following macro is defined to ease writing rich comparison functions:
[PyObject](structures.xhtml#c.PyObject "PyObject") \*`Py_RETURN_RICHCOMPARE`(VAL\_A, VAL\_B, int *op*)Return `Py_True` or `Py_False` from the function, depending on the result of a comparison. VAL\_A and VAL\_B must be orderable by C comparison operators (for example, they may be C ints or floats). The third argument specifies the requested operation, as for [`PyObject_RichCompare()`](object.xhtml#c.PyObject_RichCompare "PyObject_RichCompare").
The return value's reference count is properly incremented.
On error, sets an exception and returns NULL from the function.
3\.7 新版功能.
Py\_ssize\_t `PyTypeObject.tp_weaklistoffset`If the instances of this type are weakly referenceable, this field is greater than zero and contains the offset in the instance structure of the weak reference list head (ignoring the GC header, if present); this offset is used by `PyObject_ClearWeakRefs()` and the `PyWeakref_*()` functions. The instance structure needs to include a field of type [`PyObject*`](structures.xhtml#c.PyObject "PyObject") which is initialized to *NULL*.
Do not confuse this field with [`tp_weaklist`](#c.PyTypeObject.tp_weaklist "PyTypeObject.tp_weaklist"); that is the list head for weak references to the type object itself.
This field is inherited by subtypes, but see the rules listed below. A subtype may override this offset; this means that the subtype uses a different weak reference list head than the base type. Since the list head is always found via [`tp_weaklistoffset`](#c.PyTypeObject.tp_weaklistoffset "PyTypeObject.tp_weaklistoffset"), this should not be a problem.
When a type defined by a class statement has no [`__slots__`](../reference/datamodel.xhtml#object.__slots__ "object.__slots__") declaration, and none of its base types are weakly referenceable, the type is made weakly referenceable by adding a weak reference list head slot to the instance layout and setting the [`tp_weaklistoffset`](#c.PyTypeObject.tp_weaklistoffset "PyTypeObject.tp_weaklistoffset") of that slot's offset.
When a type's `__slots__` declaration contains a slot named `__weakref__`, that slot becomes the weak reference list head for instances of the type, and the slot's offset is stored in the type's [`tp_weaklistoffset`](#c.PyTypeObject.tp_weaklistoffset "PyTypeObject.tp_weaklistoffset").
When a type's `__slots__` declaration does not contain a slot named `__weakref__`, the type inherits its [`tp_weaklistoffset`](#c.PyTypeObject.tp_weaklistoffset "PyTypeObject.tp_weaklistoffset") from its base type.
getiterfunc `PyTypeObject.tp_iter`An optional pointer to a function that returns an iterator for the object. Its presence normally signals that the instances of this type are iterable (although sequences may be iterable without this function).
This function has the same signature as [`PyObject_GetIter()`](object.xhtml#c.PyObject_GetIter "PyObject_GetIter").
This field is inherited by subtypes.
iternextfunc `PyTypeObject.tp_iternext`An optional pointer to a function that returns the next item in an iterator. When the iterator is exhausted, it must return *NULL*; a [`StopIteration`](../library/exceptions.xhtml#StopIteration "StopIteration")exception may or may not be set. When another error occurs, it must return *NULL* too. Its presence signals that the instances of this type are iterators.
Iterator types should also define the [`tp_iter`](#c.PyTypeObject.tp_iter "PyTypeObject.tp_iter") function, and that function should return the iterator instance itself (not a new iterator instance).
This function has the same signature as [`PyIter_Next()`](iter.xhtml#c.PyIter_Next "PyIter_Next").
This field is inherited by subtypes.
struct [PyMethodDef](structures.xhtml#c.PyMethodDef "PyMethodDef")\* `PyTypeObject.tp_methods`An optional pointer to a static *NULL*-terminated array of [`PyMethodDef`](structures.xhtml#c.PyMethodDef "PyMethodDef")structures, declaring regular methods of this type.
For each entry in the array, an entry is added to the type's dictionary (see [`tp_dict`](#c.PyTypeObject.tp_dict "PyTypeObject.tp_dict") below) containing a method descriptor.
This field is not inherited by subtypes (methods are inherited through a different mechanism).
struct [PyMemberDef](structures.xhtml#c.PyMemberDef "PyMemberDef")\* `PyTypeObject.tp_members`An optional pointer to a static *NULL*-terminated array of [`PyMemberDef`](structures.xhtml#c.PyMemberDef "PyMemberDef")structures, declaring regular data members (fields or slots) of instances of this type.
For each entry in the array, an entry is added to the type's dictionary (see [`tp_dict`](#c.PyTypeObject.tp_dict "PyTypeObject.tp_dict") below) containing a member descriptor.
This field is not inherited by subtypes (members are inherited through a different mechanism).
struct [PyGetSetDef](structures.xhtml#c.PyGetSetDef "PyGetSetDef")\* `PyTypeObject.tp_getset`An optional pointer to a static *NULL*-terminated array of [`PyGetSetDef`](structures.xhtml#c.PyGetSetDef "PyGetSetDef")structures, declaring computed attributes of instances of this type.
For each entry in the array, an entry is added to the type's dictionary (see [`tp_dict`](#c.PyTypeObject.tp_dict "PyTypeObject.tp_dict") below) containing a getset descriptor.
This field is not inherited by subtypes (computed attributes are inherited through a different mechanism).
[PyTypeObject](type.xhtml#c.PyTypeObject "PyTypeObject")\* `PyTypeObject.tp_base`An optional pointer to a base type from which type properties are inherited. At this level, only single inheritance is supported; multiple inheritance require dynamically creating a type object by calling the metatype.
This field is not inherited by subtypes (obviously), but it defaults to `&PyBaseObject_Type` (which to Python programmers is known as the type [`object`](../library/functions.xhtml#object "object")).
[PyObject](structures.xhtml#c.PyObject "PyObject")\* `PyTypeObject.tp_dict`The type's dictionary is stored here by [`PyType_Ready()`](type.xhtml#c.PyType_Ready "PyType_Ready").
This field should normally be initialized to *NULL* before PyType\_Ready is called; it may also be initialized to a dictionary containing initial attributes for the type. Once [`PyType_Ready()`](type.xhtml#c.PyType_Ready "PyType_Ready") has initialized the type, extra attributes for the type may be added to this dictionary only if they don't correspond to overloaded operations (like [`__add__()`](../reference/datamodel.xhtml#object.__add__ "object.__add__")).
This field is not inherited by subtypes (though the attributes defined in here are inherited through a different mechanism).
警告
It is not safe to use [`PyDict_SetItem()`](dict.xhtml#c.PyDict_SetItem "PyDict_SetItem") on or otherwise modify [`tp_dict`](#c.PyTypeObject.tp_dict "PyTypeObject.tp_dict") with the dictionary C-API.
descrgetfunc `PyTypeObject.tp_descr_get`An optional pointer to a "descriptor get" function.
The function signature is
```
PyObject * tp_descr_get(PyObject *self, PyObject *obj, PyObject *type);
```
This field is inherited by subtypes.
descrsetfunc `PyTypeObject.tp_descr_set`An optional pointer to a function for setting and deleting a descriptor's value.
The function signature is
```
int tp_descr_set(PyObject *self, PyObject *obj, PyObject *value);
```
The *value* argument is set to *NULL* to delete the value. This field is inherited by subtypes.
Py\_ssize\_t `PyTypeObject.tp_dictoffset`If the instances of this type have a dictionary containing instance variables, this field is non-zero and contains the offset in the instances of the type of the instance variable dictionary; this offset is used by [`PyObject_GenericGetAttr()`](object.xhtml#c.PyObject_GenericGetAttr "PyObject_GenericGetAttr").
Do not confuse this field with [`tp_dict`](#c.PyTypeObject.tp_dict "PyTypeObject.tp_dict"); that is the dictionary for attributes of the type object itself.
If the value of this field is greater than zero, it specifies the offset from the start of the instance structure. If the value is less than zero, it specifies the offset from the *end* of the instance structure. A negative offset is more expensive to use, and should only be used when the instance structure contains a variable-length part. This is used for example to add an instance variable dictionary to subtypes of [`str`](../library/stdtypes.xhtml#str "str") or [`tuple`](../library/stdtypes.xhtml#tuple "tuple"). Note that the [`tp_basicsize`](#c.PyTypeObject.tp_basicsize "PyTypeObject.tp_basicsize") field should account for the dictionary added to the end in that case, even though the dictionary is not included in the basic object layout. On a system with a pointer size of 4 bytes, [`tp_dictoffset`](#c.PyTypeObject.tp_dictoffset "PyTypeObject.tp_dictoffset") should be set to `-4` to indicate that the dictionary is at the very end of the structure.
The real dictionary offset in an instance can be computed from a negative [`tp_dictoffset`](#c.PyTypeObject.tp_dictoffset "PyTypeObject.tp_dictoffset") as follows:
```
dictoffset = tp_basicsize + abs(ob_size)*tp_itemsize + tp_dictoffset
if dictoffset is not aligned on sizeof(void*):
round up to sizeof(void*)
```
where [`tp_basicsize`](#c.PyTypeObject.tp_basicsize "PyTypeObject.tp_basicsize"), [`tp_itemsize`](#c.PyTypeObject.tp_itemsize "PyTypeObject.tp_itemsize") and [`tp_dictoffset`](#c.PyTypeObject.tp_dictoffset "PyTypeObject.tp_dictoffset") are taken from the type object, and `ob_size` is taken from the instance. The absolute value is taken because ints use the sign of `ob_size` to store the sign of the number. (There's never a need to do this calculation yourself; it is done for you by `_PyObject_GetDictPtr()`.)
This field is inherited by subtypes, but see the rules listed below. A subtype may override this offset; this means that the subtype instances store the dictionary at a difference offset than the base type. Since the dictionary is always found via [`tp_dictoffset`](#c.PyTypeObject.tp_dictoffset "PyTypeObject.tp_dictoffset"), this should not be a problem.
When a type defined by a class statement has no [`__slots__`](../reference/datamodel.xhtml#object.__slots__ "object.__slots__") declaration, and none of its base types has an instance variable dictionary, a dictionary slot is added to the instance layout and the [`tp_dictoffset`](#c.PyTypeObject.tp_dictoffset "PyTypeObject.tp_dictoffset") is set to that slot's offset.
When a type defined by a class statement has a `__slots__` declaration, the type inherits its [`tp_dictoffset`](#c.PyTypeObject.tp_dictoffset "PyTypeObject.tp_dictoffset") from its base type.
(Adding a slot named [`__dict__`](../library/stdtypes.xhtml#object.__dict__ "object.__dict__") to the `__slots__` declaration does not have the expected effect, it just causes confusion. Maybe this should be added as a feature just like `__weakref__` though.)
initproc `PyTypeObject.tp_init`An optional pointer to an instance initialization function.
This function corresponds to the [`__init__()`](../reference/datamodel.xhtml#object.__init__ "object.__init__") method of classes. Like [`__init__()`](../reference/datamodel.xhtml#object.__init__ "object.__init__"), it is possible to create an instance without calling [`__init__()`](../reference/datamodel.xhtml#object.__init__ "object.__init__"), and it is possible to reinitialize an instance by calling its [`__init__()`](../reference/datamodel.xhtml#object.__init__ "object.__init__") method again.
The function signature is
```
int tp_init(PyObject *self, PyObject *args, PyObject *kwds)
```
The self argument is the instance to be initialized; the *args* and *kwds*arguments represent positional and keyword arguments of the call to [`__init__()`](../reference/datamodel.xhtml#object.__init__ "object.__init__").
The [`tp_init`](#c.PyTypeObject.tp_init "PyTypeObject.tp_init") function, if not *NULL*, is called when an instance is created normally by calling its type, after the type's [`tp_new`](#c.PyTypeObject.tp_new "PyTypeObject.tp_new") function has returned an instance of the type. If the [`tp_new`](#c.PyTypeObject.tp_new "PyTypeObject.tp_new") function returns an instance of some other type that is not a subtype of the original type, no [`tp_init`](#c.PyTypeObject.tp_init "PyTypeObject.tp_init") function is called; if [`tp_new`](#c.PyTypeObject.tp_new "PyTypeObject.tp_new") returns an instance of a subtype of the original type, the subtype's [`tp_init`](#c.PyTypeObject.tp_init "PyTypeObject.tp_init") is called.
This field is inherited by subtypes.
allocfunc `PyTypeObject.tp_alloc`An optional pointer to an instance allocation function.
The function signature is
```
PyObject *tp_alloc(PyTypeObject *self, Py_ssize_t nitems)
```
The purpose of this function is to separate memory allocation from memory initialization. It should return a pointer to a block of memory of adequate length for the instance, suitably aligned, and initialized to zeros, but with `ob_refcnt` set to `1` and `ob_type` set to the type argument. If the type's [`tp_itemsize`](#c.PyTypeObject.tp_itemsize "PyTypeObject.tp_itemsize") is non-zero, the object's `ob_size` field should be initialized to *nitems* and the length of the allocated memory block should be `tp_basicsize + nitems*tp_itemsize`, rounded up to a multiple of `sizeof(void*)`; otherwise, *nitems* is not used and the length of the block should be [`tp_basicsize`](#c.PyTypeObject.tp_basicsize "PyTypeObject.tp_basicsize").
Do not use this function to do any other instance initialization, not even to allocate additional memory; that should be done by [`tp_new`](#c.PyTypeObject.tp_new "PyTypeObject.tp_new").
This field is inherited by static subtypes, but not by dynamic subtypes (subtypes created by a class statement); in the latter, this field is always set to [`PyType_GenericAlloc()`](type.xhtml#c.PyType_GenericAlloc "PyType_GenericAlloc"), to force a standard heap allocation strategy. That is also the recommended value for statically defined types.
newfunc `PyTypeObject.tp_new`An optional pointer to an instance creation function.
If this function is *NULL* for a particular type, that type cannot be called to create new instances; presumably there is some other way to create instances, like a factory function.
The function signature is
```
PyObject *tp_new(PyTypeObject *subtype, PyObject *args, PyObject *kwds)
```
The subtype argument is the type of the object being created; the *args* and *kwds* arguments represent positional and keyword arguments of the call to the type. Note that subtype doesn't have to equal the type whose [`tp_new`](#c.PyTypeObject.tp_new "PyTypeObject.tp_new")function is called; it may be a subtype of that type (but not an unrelated type).
The [`tp_new`](#c.PyTypeObject.tp_new "PyTypeObject.tp_new") function should call `subtype->tp_alloc(subtype, nitems)`to allocate space for the object, and then do only as much further initialization as is absolutely necessary. Initialization that can safely be ignored or repeated should be placed in the [`tp_init`](#c.PyTypeObject.tp_init "PyTypeObject.tp_init") handler. A good rule of thumb is that for immutable types, all initialization should take place in [`tp_new`](#c.PyTypeObject.tp_new "PyTypeObject.tp_new"), while for mutable types, most initialization should be deferred to [`tp_init`](#c.PyTypeObject.tp_init "PyTypeObject.tp_init").
This field is inherited by subtypes, except it is not inherited by static types whose [`tp_base`](#c.PyTypeObject.tp_base "PyTypeObject.tp_base") is *NULL* or `&PyBaseObject_Type`.
destructor `PyTypeObject.tp_free`An optional pointer to an instance deallocation function. Its signature is `freefunc`:
```
void tp_free(void *)
```
An initializer that is compatible with this signature is [`PyObject_Free()`](memory.xhtml#c.PyObject_Free "PyObject_Free").
This field is inherited by static subtypes, but not by dynamic subtypes (subtypes created by a class statement); in the latter, this field is set to a deallocator suitable to match [`PyType_GenericAlloc()`](type.xhtml#c.PyType_GenericAlloc "PyType_GenericAlloc") and the value of the [`Py_TPFLAGS_HAVE_GC`](#Py_TPFLAGS_HAVE_GC "Py_TPFLAGS_HAVE_GC") flag bit.
[inquiry](gcsupport.xhtml#c.inquiry "inquiry")`PyTypeObject.tp_is_gc`An optional pointer to a function called by the garbage collector.
The garbage collector needs to know whether a particular object is collectible or not. Normally, it is sufficient to look at the object's type's [`tp_flags`](#c.PyTypeObject.tp_flags "PyTypeObject.tp_flags") field, and check the [`Py_TPFLAGS_HAVE_GC`](#Py_TPFLAGS_HAVE_GC "Py_TPFLAGS_HAVE_GC") flag bit. But some types have a mixture of statically and dynamically allocated instances, and the statically allocated instances are not collectible. Such types should define this function; it should return `1` for a collectible instance, and `0` for a non-collectible instance. The signature is
```
int tp_is_gc(PyObject *self)
```
(The only example of this are types themselves. The metatype, [`PyType_Type`](type.xhtml#c.PyType_Type "PyType_Type"), defines this function to distinguish between statically and dynamically allocated types.)
This field is inherited by subtypes.
[PyObject](structures.xhtml#c.PyObject "PyObject")\* `PyTypeObject.tp_bases`Tuple of base types.
This is set for types created by a class statement. It should be *NULL* for statically defined types.
This field is not inherited.
[PyObject](structures.xhtml#c.PyObject "PyObject")\* `PyTypeObject.tp_mro`Tuple containing the expanded set of base types, starting with the type itself and ending with [`object`](../library/functions.xhtml#object "object"), in Method Resolution Order.
This field is not inherited; it is calculated fresh by [`PyType_Ready()`](type.xhtml#c.PyType_Ready "PyType_Ready").
destructor `PyTypeObject.tp_finalize`An optional pointer to an instance finalization function. Its signature is `destructor`:
```
void tp_finalize(PyObject *)
```
If [`tp_finalize`](#c.PyTypeObject.tp_finalize "PyTypeObject.tp_finalize") is set, the interpreter calls it once when finalizing an instance. It is called either from the garbage collector (if the instance is part of an isolated reference cycle) or just before the object is deallocated. Either way, it is guaranteed to be called before attempting to break reference cycles, ensuring that it finds the object in a sane state.
[`tp_finalize`](#c.PyTypeObject.tp_finalize "PyTypeObject.tp_finalize") should not mutate the current exception status; therefore, a recommended way to write a non-trivial finalizer is:
```
static void
local_finalize(PyObject *self)
{
PyObject *error_type, *error_value, *error_traceback;
/* Save the current exception, if any. */
PyErr_Fetch(&error_type, &error_value, &error_traceback);
/* ... */
/* Restore the saved exception. */
PyErr_Restore(error_type, error_value, error_traceback);
}
```
For this field to be taken into account (even through inheritance), you must also set the [`Py_TPFLAGS_HAVE_FINALIZE`](#Py_TPFLAGS_HAVE_FINALIZE "Py_TPFLAGS_HAVE_FINALIZE") flags bit.
This field is inherited by subtypes.
3\.4 新版功能.
參見
"Safe object finalization" ([**PEP 442**](https://www.python.org/dev/peps/pep-0442) \[https://www.python.org/dev/peps/pep-0442\])
[PyObject](structures.xhtml#c.PyObject "PyObject")\* `PyTypeObject.tp_cache`Unused. Not inherited. Internal use only.
[PyObject](structures.xhtml#c.PyObject "PyObject")\* `PyTypeObject.tp_subclasses`List of weak references to subclasses. Not inherited. Internal use only.
[PyObject](structures.xhtml#c.PyObject "PyObject")\* `PyTypeObject.tp_weaklist`Weak reference list head, for weak references to this type object. Not inherited. Internal use only.
The remaining fields are only defined if the feature test macro `COUNT_ALLOCS` is defined, and are for internal use only. They are documented here for completeness. None of these fields are inherited by subtypes.
Py\_ssize\_t `PyTypeObject.tp_allocs`Number of allocations.
Py\_ssize\_t `PyTypeObject.tp_frees`Number of frees.
Py\_ssize\_t `PyTypeObject.tp_maxalloc`Maximum simultaneously allocated objects.
[PyTypeObject](type.xhtml#c.PyTypeObject "PyTypeObject")\* `PyTypeObject.tp_next`Pointer to the next type object with a non-zero [`tp_allocs`](#c.PyTypeObject.tp_allocs "PyTypeObject.tp_allocs") field.
Also, note that, in a garbage collected Python, tp\_dealloc may be called from any Python thread, not just the thread which created the object (if the object becomes part of a refcount cycle, that cycle might be collected by a garbage collection on any thread). This is not a problem for Python API calls, since the thread on which tp\_dealloc is called will own the Global Interpreter Lock (GIL). However, if the object being destroyed in turn destroys objects from some other C or C++ library, care should be taken to ensure that destroying those objects on the thread which called tp\_dealloc will not violate any assumptions of the library.
# Number Object Structures
`PyNumberMethods`This structure holds pointers to the functions which an object uses to implement the number protocol. Each function is used by the function of similar name documented in the [數字協議](number.xhtml#number) section.
Here is the structure definition:
```
typedef struct {
binaryfunc nb_add;
binaryfunc nb_subtract;
binaryfunc nb_multiply;
binaryfunc nb_remainder;
binaryfunc nb_divmod;
ternaryfunc nb_power;
unaryfunc nb_negative;
unaryfunc nb_positive;
unaryfunc nb_absolute;
inquiry nb_bool;
unaryfunc nb_invert;
binaryfunc nb_lshift;
binaryfunc nb_rshift;
binaryfunc nb_and;
binaryfunc nb_xor;
binaryfunc nb_or;
unaryfunc nb_int;
void *nb_reserved;
unaryfunc nb_float;
binaryfunc nb_inplace_add;
binaryfunc nb_inplace_subtract;
binaryfunc nb_inplace_multiply;
binaryfunc nb_inplace_remainder;
ternaryfunc nb_inplace_power;
binaryfunc nb_inplace_lshift;
binaryfunc nb_inplace_rshift;
binaryfunc nb_inplace_and;
binaryfunc nb_inplace_xor;
binaryfunc nb_inplace_or;
binaryfunc nb_floor_divide;
binaryfunc nb_true_divide;
binaryfunc nb_inplace_floor_divide;
binaryfunc nb_inplace_true_divide;
unaryfunc nb_index;
binaryfunc nb_matrix_multiply;
binaryfunc nb_inplace_matrix_multiply;
} PyNumberMethods;
```
注解
Binary and ternary functions must check the type of all their operands, and implement the necessary conversions (at least one of the operands is an instance of the defined type). If the operation is not defined for the given operands, binary and ternary functions must return `Py_NotImplemented`, if another error occurred they must return `NULL`and set an exception.
注解
The `nb_reserved` field should always be `NULL`. It was previously called `nb_long`, and was renamed in Python 3.0.1.
# Mapping Object Structures
`PyMappingMethods`This structure holds pointers to the functions which an object uses to implement the mapping protocol. It has three members:
lenfunc `PyMappingMethods.mp_length`This function is used by [`PyMapping_Size()`](mapping.xhtml#c.PyMapping_Size "PyMapping_Size") and [`PyObject_Size()`](object.xhtml#c.PyObject_Size "PyObject_Size"), and has the same signature. This slot may be set to *NULL* if the object has no defined length.
binaryfunc `PyMappingMethods.mp_subscript`This function is used by [`PyObject_GetItem()`](object.xhtml#c.PyObject_GetItem "PyObject_GetItem") and [`PySequence_GetSlice()`](sequence.xhtml#c.PySequence_GetSlice "PySequence_GetSlice"), and has the same signature as `PyObject_GetItem()`. This slot must be filled for the [`PyMapping_Check()`](mapping.xhtml#c.PyMapping_Check "PyMapping_Check") function to return `1`, it can be *NULL*otherwise.
objobjargproc `PyMappingMethods.mp_ass_subscript`This function is used by [`PyObject_SetItem()`](object.xhtml#c.PyObject_SetItem "PyObject_SetItem"), [`PyObject_DelItem()`](object.xhtml#c.PyObject_DelItem "PyObject_DelItem"), `PyObject_SetSlice()` and `PyObject_DelSlice()`. It has the same signature as `PyObject_SetItem()`, but *v* can also be set to *NULL* to delete an item. If this slot is *NULL*, the object does not support item assignment and deletion.
# Sequence Object Structures
`PySequenceMethods`This structure holds pointers to the functions which an object uses to implement the sequence protocol.
lenfunc `PySequenceMethods.sq_length`This function is used by [`PySequence_Size()`](sequence.xhtml#c.PySequence_Size "PySequence_Size") and [`PyObject_Size()`](object.xhtml#c.PyObject_Size "PyObject_Size"), and has the same signature. It is also used for handling negative indices via the [`sq_item`](#c.PySequenceMethods.sq_item "PySequenceMethods.sq_item")and the [`sq_ass_item`](#c.PySequenceMethods.sq_ass_item "PySequenceMethods.sq_ass_item") slots.
binaryfunc `PySequenceMethods.sq_concat`This function is used by [`PySequence_Concat()`](sequence.xhtml#c.PySequence_Concat "PySequence_Concat") and has the same signature. It is also used by the `+` operator, after trying the numeric addition via the `nb_add` slot.
ssizeargfunc `PySequenceMethods.sq_repeat`This function is used by [`PySequence_Repeat()`](sequence.xhtml#c.PySequence_Repeat "PySequence_Repeat") and has the same signature. It is also used by the `*` operator, after trying numeric multiplication via the `nb_multiply` slot.
ssizeargfunc `PySequenceMethods.sq_item`This function is used by [`PySequence_GetItem()`](sequence.xhtml#c.PySequence_GetItem "PySequence_GetItem") and has the same signature. It is also used by [`PyObject_GetItem()`](object.xhtml#c.PyObject_GetItem "PyObject_GetItem"), after trying the subscription via the [`mp_subscript`](#c.PyMappingMethods.mp_subscript "PyMappingMethods.mp_subscript") slot. This slot must be filled for the [`PySequence_Check()`](sequence.xhtml#c.PySequence_Check "PySequence_Check")function to return `1`, it can be *NULL* otherwise.
Negative indexes are handled as follows: if the `sq_length` slot is filled, it is called and the sequence length is used to compute a positive index which is passed to `sq_item`. If `sq_length` is *NULL*, the index is passed as is to the function.
ssizeobjargproc `PySequenceMethods.sq_ass_item`This function is used by [`PySequence_SetItem()`](sequence.xhtml#c.PySequence_SetItem "PySequence_SetItem") and has the same signature. It is also used by [`PyObject_SetItem()`](object.xhtml#c.PyObject_SetItem "PyObject_SetItem") and [`PyObject_DelItem()`](object.xhtml#c.PyObject_DelItem "PyObject_DelItem"), after trying the item assignment and deletion via the [`mp_ass_subscript`](#c.PyMappingMethods.mp_ass_subscript "PyMappingMethods.mp_ass_subscript") slot. This slot may be left to *NULL* if the object does not support item assignment and deletion.
objobjproc `PySequenceMethods.sq_contains`This function may be used by [`PySequence_Contains()`](sequence.xhtml#c.PySequence_Contains "PySequence_Contains") and has the same signature. This slot may be left to *NULL*, in this case `PySequence_Contains()` simply traverses the sequence until it finds a match.
binaryfunc `PySequenceMethods.sq_inplace_concat`This function is used by [`PySequence_InPlaceConcat()`](sequence.xhtml#c.PySequence_InPlaceConcat "PySequence_InPlaceConcat") and has the same signature. It should modify its first operand, and return it. This slot may be left to *NULL*, in this case `PySequence_InPlaceConcat()`will fall back to [`PySequence_Concat()`](sequence.xhtml#c.PySequence_Concat "PySequence_Concat"). It is also used by the augmented assignment `+=`, after trying numeric in-place addition via the `nb_inplace_add` slot.
ssizeargfunc `PySequenceMethods.sq_inplace_repeat`This function is used by [`PySequence_InPlaceRepeat()`](sequence.xhtml#c.PySequence_InPlaceRepeat "PySequence_InPlaceRepeat") and has the same signature. It should modify its first operand, and return it. This slot may be left to *NULL*, in this case `PySequence_InPlaceRepeat()`will fall back to [`PySequence_Repeat()`](sequence.xhtml#c.PySequence_Repeat "PySequence_Repeat"). It is also used by the augmented assignment `*=`, after trying numeric in-place multiplication via the `nb_inplace_multiply` slot.
# Buffer Object Structures
`PyBufferProcs`This structure holds pointers to the functions required by the [Buffer protocol](buffer.xhtml#bufferobjects). The protocol defines how an exporter object can expose its internal data to consumer objects.
getbufferproc `PyBufferProcs.bf_getbuffer`The signature of this function is:
```
int (PyObject *exporter, Py_buffer *view, int flags);
```
Handle a request to *exporter* to fill in *view* as specified by *flags*. Except for point (3), an implementation of this function MUST take these steps:
1. Check if the request can be met. If not, raise `PyExc_BufferError`, set `view->obj` to *NULL* and return `-1`.
2. Fill in the requested fields.
3. Increment an internal counter for the number of exports.
4. Set `view->obj` to *exporter* and increment `view->obj`.
5. Return `0`.
If *exporter* is part of a chain or tree of buffer providers, two main schemes can be used:
- Re-export: Each member of the tree acts as the exporting object and sets `view->obj` to a new reference to itself.
- Redirect: The buffer request is redirected to the root object of the tree. Here, `view->obj` will be a new reference to the root object.
The individual fields of *view* are described in section [Buffer structure](buffer.xhtml#buffer-structure), the rules how an exporter must react to specific requests are in section [Buffer request types](buffer.xhtml#buffer-request-types).
All memory pointed to in the [`Py_buffer`](buffer.xhtml#c.Py_buffer "Py_buffer") structure belongs to the exporter and must remain valid until there are no consumers left. [`format`](buffer.xhtml#c.Py_buffer.format "Py_buffer.format"), [`shape`](buffer.xhtml#c.Py_buffer.shape "Py_buffer.shape"), [`strides`](buffer.xhtml#c.Py_buffer.strides "Py_buffer.strides"), [`suboffsets`](buffer.xhtml#c.Py_buffer.suboffsets "Py_buffer.suboffsets")and [`internal`](buffer.xhtml#c.Py_buffer.internal "Py_buffer.internal")are read-only for the consumer.
[`PyBuffer_FillInfo()`](buffer.xhtml#c.PyBuffer_FillInfo "PyBuffer_FillInfo") provides an easy way of exposing a simple bytes buffer while dealing correctly with all request types.
[`PyObject_GetBuffer()`](buffer.xhtml#c.PyObject_GetBuffer "PyObject_GetBuffer") is the interface for the consumer that wraps this function.
releasebufferproc `PyBufferProcs.bf_releasebuffer`The signature of this function is:
```
void (PyObject *exporter, Py_buffer *view);
```
Handle a request to release the resources of the buffer. If no resources need to be released, [`PyBufferProcs.bf_releasebuffer`](#c.PyBufferProcs.bf_releasebuffer "PyBufferProcs.bf_releasebuffer") may be *NULL*. Otherwise, a standard implementation of this function will take these optional steps:
1. Decrement an internal counter for the number of exports.
2. If the counter is `0`, free all memory associated with *view*.
The exporter MUST use the [`internal`](buffer.xhtml#c.Py_buffer.internal "Py_buffer.internal") field to keep track of buffer-specific resources. This field is guaranteed to remain constant, while a consumer MAY pass a copy of the original buffer as the *view* argument.
This function MUST NOT decrement `view->obj`, since that is done automatically in [`PyBuffer_Release()`](buffer.xhtml#c.PyBuffer_Release "PyBuffer_Release") (this scheme is useful for breaking reference cycles).
[`PyBuffer_Release()`](buffer.xhtml#c.PyBuffer_Release "PyBuffer_Release") is the interface for the consumer that wraps this function.
# Async Object Structures
3\.5 新版功能.
`PyAsyncMethods`This structure holds pointers to the functions required to implement [awaitable](../glossary.xhtml#term-awaitable) and [asynchronous iterator](../glossary.xhtml#term-asynchronous-iterator) objects.
Here is the structure definition:
```
typedef struct {
unaryfunc am_await;
unaryfunc am_aiter;
unaryfunc am_anext;
} PyAsyncMethods;
```
unaryfunc `PyAsyncMethods.am_await`The signature of this function is:
```
PyObject *am_await(PyObject *self)
```
The returned object must be an iterator, i.e. [`PyIter_Check()`](iter.xhtml#c.PyIter_Check "PyIter_Check") must return `1` for it.
This slot may be set to *NULL* if an object is not an [awaitable](../glossary.xhtml#term-awaitable).
unaryfunc `PyAsyncMethods.am_aiter`The signature of this function is:
```
PyObject *am_aiter(PyObject *self)
```
Must return an [awaitable](../glossary.xhtml#term-awaitable) object. See [`__anext__()`](../reference/datamodel.xhtml#object.__anext__ "object.__anext__") for details.
This slot may be set to *NULL* if an object does not implement asynchronous iteration protocol.
unaryfunc `PyAsyncMethods.am_anext`The signature of this function is:
```
PyObject *am_anext(PyObject *self)
```
Must return an [awaitable](../glossary.xhtml#term-awaitable) object. See [`__anext__()`](../reference/datamodel.xhtml#object.__anext__ "object.__anext__") for details. This slot may be set to *NULL*.
### 導航
- [索引](../genindex.xhtml "總目錄")
- [模塊](../py-modindex.xhtml "Python 模塊索引") |
- [下一頁](gcsupport.xhtml "使對象類型支持循環垃圾回收") |
- [上一頁](structures.xhtml "Common Object Structures") |
- 
- [Python](https://www.python.org/) ?
- zh\_CN 3.7.3 [文檔](../index.xhtml) ?
- [Python/C API 參考手冊](index.xhtml) ?
- [對象實現支持](objimpl.xhtml) ?
- $('.inline-search').show(0); |
? [版權所有](../copyright.xhtml) 2001-2019, Python Software Foundation.
Python 軟件基金會是一個非盈利組織。 [請捐助。](https://www.python.org/psf/donations/)
最后更新于 5月 21, 2019. [發現了問題](../bugs.xhtml)?
使用[Sphinx](http://sphinx.pocoo.org/)1.8.4 創建。
- 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