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<li><a class="reference internal" href="#">Type Objects</a><ul>
<li><a class="reference internal" href="#creating-heap-allocated-types">Creating Heap-Allocated Types</a></li>
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 <section id="type-objects">
<h1>Type Objects<a class="headerlink" href="#type-objects" title="Permalink to this headline">¶</a></h1>
<dl class="c type">
<dt class="sig sig-object c" id="c.PyTypeObject">
type PyTypeObject<a class="headerlink" href="#c.PyTypeObject" title="Permalink to this definition">¶</a> </dt>
<dd> Part of the <a class="reference internal" href="stable.html#stable">Limited API</a> (as an opaque struct).The C structure of the objects used to describe built-in types.
</dd></dl>

<dl class="c var">
<dt class="sig sig-object c" id="c.PyType_Type">
<a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a> PyType_Type<a class="headerlink" href="#c.PyType_Type" title="Permalink to this definition">¶</a> </dt>
<dd> Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a>.This is the type object for type objects; it is the same object as
<a class="reference internal" href="../library/functions.html#type" title="type"><code class="xref py py-class docutils literal notranslate">type</code></a> in the Python layer.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_Check">
int PyType_Check(<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *o)<a class="headerlink" href="#c.PyType_Check" title="Permalink to this definition">¶</a> </dt>
<dd>Return non-zero if the object o is a type object, including instances of
types derived from the standard type object. Return 0 in all other cases.
This function always succeeds.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_CheckExact">
int PyType_CheckExact(<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *o)<a class="headerlink" href="#c.PyType_CheckExact" title="Permalink to this definition">¶</a> </dt>
<dd>Return non-zero if the object o is a type object, but not a subtype of
the standard type object. Return 0 in all other cases. This function
always succeeds.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_ClearCache">
unsigned int PyType_ClearCache()<a class="headerlink" href="#c.PyType_ClearCache" title="Permalink to this definition">¶</a> </dt>
<dd> Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a>.Clear the internal lookup cache. Return the current version tag.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_GetFlags">
unsigned long PyType_GetFlags(<a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a> *type)<a class="headerlink" href="#c.PyType_GetFlags" title="Permalink to this definition">¶</a> </dt>
<dd> Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a>.Return the <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_flags" title="PyTypeObject.tp_flags"><code class="xref c c-member docutils literal notranslate">tp_flags</code></a> member of type. This function is primarily
meant for use with <code class="docutils literal notranslate">Py_LIMITED_API</code>; the individual flag bits are
guaranteed to be stable across Python releases, but access to
<a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_flags" title="PyTypeObject.tp_flags"><code class="xref c c-member docutils literal notranslate">tp_flags</code></a> itself is not part of the limited API.
<div class="versionadded">
New in version 3.2.
</div>
<div class="versionchanged">
Changed in version 3.4: The return type is now <code class="docutils literal notranslate">unsigned long</code> rather than <code class="docutils literal notranslate">long</code>.
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_Modified">
void PyType_Modified(<a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a> *type)<a class="headerlink" href="#c.PyType_Modified" title="Permalink to this definition">¶</a> </dt>
<dd> Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a>.Invalidate the internal lookup cache for the type and all of its
subtypes. This function must be called after any manual
modification of the attributes or base classes of the type.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_HasFeature">
int PyType_HasFeature(<a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a> *o, int feature)<a class="headerlink" href="#c.PyType_HasFeature" title="Permalink to this definition">¶</a> </dt>
<dd>Return non-zero if the type object o sets the feature feature.
Type features are denoted by single bit flags.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_IS_GC">
int PyType_IS_GC(<a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a> *o)<a class="headerlink" href="#c.PyType_IS_GC" title="Permalink to this definition">¶</a> </dt>
<dd>Return true if the type object includes support for the cycle detector; this
tests the type flag <a class="reference internal" href="typeobj.html#Py_TPFLAGS_HAVE_GC" title="Py_TPFLAGS_HAVE_GC"><code class="xref py py-const docutils literal notranslate">Py_TPFLAGS_HAVE_GC</code></a>.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_IsSubtype">
int PyType_IsSubtype(<a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a> *a, <a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a> *b)<a class="headerlink" href="#c.PyType_IsSubtype" title="Permalink to this definition">¶</a> </dt>
<dd> Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a>.Return true if a is a subtype of b.
This function only checks for actual subtypes, which means that
<a class="reference internal" href="../reference/datamodel.html#class.__subclasscheck__" title="class.__subclasscheck__"><code class="xref py py-meth docutils literal notranslate">__subclasscheck__()</code></a> is not called on b. Call
<a class="reference internal" href="object.html#c.PyObject_IsSubclass" title="PyObject_IsSubclass"><code class="xref c c-func docutils literal notranslate">PyObject_IsSubclass()</code></a> to do the same check that <a class="reference internal" href="../library/functions.html#issubclass" title="issubclass"><code class="xref py py-func docutils literal notranslate">issubclass()</code></a>
would do.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_GenericAlloc">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *PyType_GenericAlloc(<a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a> *type, <a class="reference internal" href="intro.html#c.Py_ssize_t" title="Py_ssize_t">Py_ssize_t</a> nitems)<a class="headerlink" href="#c.PyType_GenericAlloc" title="Permalink to this definition">¶</a> </dt>
<dd>Return value: New reference. Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a>.Generic handler for the <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_alloc" title="PyTypeObject.tp_alloc"><code class="xref c c-member docutils literal notranslate">tp_alloc</code></a> slot of a type object. Use
Python’s default memory allocation mechanism to allocate a new instance and
initialize all its contents to <code class="docutils literal notranslate">NULL</code>.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_GenericNew">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *PyType_GenericNew(<a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a> *type, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *args, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *kwds)<a class="headerlink" href="#c.PyType_GenericNew" title="Permalink to this definition">¶</a> </dt>
<dd>Return value: New reference. Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a>.Generic handler for the <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_new" title="PyTypeObject.tp_new"><code class="xref c c-member docutils literal notranslate">tp_new</code></a> slot of a type object. Create a
new instance using the type’s <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_alloc" title="PyTypeObject.tp_alloc"><code class="xref c c-member docutils literal notranslate">tp_alloc</code></a> slot.
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_Ready">
int PyType_Ready(<a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a> *type)<a class="headerlink" href="#c.PyType_Ready" title="Permalink to this definition">¶</a> </dt>
<dd> Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a>.Finalize a type object. This should be called on all type objects to finish
their initialization. This function is responsible for adding inherited slots
from a type’s base class. Return <code class="docutils literal notranslate">0</code> on success, or return <code class="docutils literal notranslate">-1</code> and sets an
exception on error.
<div class="admonition note">
Note
If some of the base classes implements the GC protocol and the provided
type does not include the <a class="reference internal" href="typeobj.html#Py_TPFLAGS_HAVE_GC" title="Py_TPFLAGS_HAVE_GC"><code class="xref py py-const docutils literal notranslate">Py_TPFLAGS_HAVE_GC</code></a> in its flags, then
the GC protocol will be automatically implemented from its parents. On
the contrary, if the type being created does include
<a class="reference internal" href="typeobj.html#Py_TPFLAGS_HAVE_GC" title="Py_TPFLAGS_HAVE_GC"><code class="xref py py-const docutils literal notranslate">Py_TPFLAGS_HAVE_GC</code></a> in its flags then it must implement the
GC protocol itself by at least implementing the
<a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_traverse" title="PyTypeObject.tp_traverse"><code class="xref c c-member docutils literal notranslate">tp_traverse</code></a> handle.
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_GetSlot">
void *PyType_GetSlot(<a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a> *type, int slot)<a class="headerlink" href="#c.PyType_GetSlot" title="Permalink to this definition">¶</a> </dt>
<dd> Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a> since version 3.4.Return the function pointer stored in the given slot. If the
result is <code class="docutils literal notranslate">NULL</code>, this indicates that either the slot is <code class="docutils literal notranslate">NULL</code>,
or that the function was called with invalid parameters.
Callers will typically cast the result pointer into the appropriate
function type.
See <code class="xref c c-member docutils literal notranslate">PyType_Slot.slot</code> for possible values of the slot argument.
<div class="versionadded">
New in version 3.4.
</div>
<div class="versionchanged">
Changed in version 3.10: <a class="reference internal" href="#c.PyType_GetSlot" title="PyType_GetSlot"><code class="xref c c-func docutils literal notranslate">PyType_GetSlot()</code></a> can now accept all types.
Previously, it was limited to <a class="reference internal" href="typeobj.html#heap-types">heap types</a>.
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_GetModule">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *PyType_GetModule(<a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a> *type)<a class="headerlink" href="#c.PyType_GetModule" title="Permalink to this definition">¶</a> </dt>
<dd> Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a> since version 3.10.Return the module object associated with the given type when the type was
created using <a class="reference internal" href="#c.PyType_FromModuleAndSpec" title="PyType_FromModuleAndSpec"><code class="xref c c-func docutils literal notranslate">PyType_FromModuleAndSpec()</code></a>.
If no module is associated with the given type, sets <a class="reference internal" href="../library/exceptions.html#TypeError" title="TypeError"><code class="xref py py-class docutils literal notranslate">TypeError</code></a>
and returns <code class="docutils literal notranslate">NULL</code>.
This function is usually used to get the module in which a method is defined.
Note that in such a method, <code class="docutils literal notranslate">PyType_GetModule(Py_TYPE(self))</code>
may not return the intended result.
<code class="docutils literal notranslate">Py_TYPE(self)</code> may be a subclass of the intended class, and subclasses
are not necessarily defined in the same module as their superclass.
See <a class="reference internal" href="structures.html#c.PyCMethod" title="PyCMethod"><code class="xref c c-type docutils literal notranslate">PyCMethod</code></a> to get the class that defines the method.
<div class="versionadded">
New in version 3.9.
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_GetModuleState">
void *PyType_GetModuleState(<a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a> *type)<a class="headerlink" href="#c.PyType_GetModuleState" title="Permalink to this definition">¶</a> </dt>
<dd> Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a> since version 3.10.Return the state of the module object associated with the given type.
This is a shortcut for calling <a class="reference internal" href="module.html#c.PyModule_GetState" title="PyModule_GetState"><code class="xref c c-func docutils literal notranslate">PyModule_GetState()</code></a> on the result
of <a class="reference internal" href="#c.PyType_GetModule" title="PyType_GetModule"><code class="xref c c-func docutils literal notranslate">PyType_GetModule()</code></a>.
If no module is associated with the given type, sets <a class="reference internal" href="../library/exceptions.html#TypeError" title="TypeError"><code class="xref py py-class docutils literal notranslate">TypeError</code></a>
and returns <code class="docutils literal notranslate">NULL</code>.
If the type has an associated module but its state is <code class="docutils literal notranslate">NULL</code>,
returns <code class="docutils literal notranslate">NULL</code> without setting an exception.
<div class="versionadded">
New in version 3.9.
</div>
</dd></dl>

<section id="creating-heap-allocated-types">
<h2>Creating Heap-Allocated Types<a class="headerlink" href="#creating-heap-allocated-types" title="Permalink to this headline">¶</a></h2>
The following functions and structs are used to create
<a class="reference internal" href="typeobj.html#heap-types">heap types</a>.
<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_FromModuleAndSpec">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *PyType_FromModuleAndSpec(<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *module, <a class="reference internal" href="#c.PyType_Spec" title="PyType_Spec">PyType_Spec</a> *spec, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *bases)<a class="headerlink" href="#c.PyType_FromModuleAndSpec" title="Permalink to this definition">¶</a> </dt>
<dd>Return value: New reference. Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a> since version 3.10.Creates and returns a <a class="reference internal" href="typeobj.html#heap-types">heap type</a> from the spec
(<a class="reference internal" href="typeobj.html#Py_TPFLAGS_HEAPTYPE" title="Py_TPFLAGS_HEAPTYPE"><code class="xref py py-const docutils literal notranslate">Py_TPFLAGS_HEAPTYPE</code></a>).
The bases argument can be used to specify base classes; it can either
be only one class or a tuple of classes.
If bases is <code class="docutils literal notranslate">NULL</code>, the Py_tp_bases slot is used instead.
If that also is <code class="docutils literal notranslate">NULL</code>, the Py_tp_base slot is used instead.
If that also is <code class="docutils literal notranslate">NULL</code>, the new type derives from <a class="reference internal" href="../library/functions.html#object" title="object"><code class="xref py py-class docutils literal notranslate">object</code></a>.
The module argument can be used to record the module in which the new
class is defined. It must be a module object or <code class="docutils literal notranslate">NULL</code>.
If not <code class="docutils literal notranslate">NULL</code>, the module is associated with the new type and can later be
retrieved with <a class="reference internal" href="#c.PyType_GetModule" title="PyType_GetModule"><code class="xref c c-func docutils literal notranslate">PyType_GetModule()</code></a>.
The associated module is not inherited by subclasses; it must be specified
for each class individually.
This function calls <a class="reference internal" href="#c.PyType_Ready" title="PyType_Ready"><code class="xref c c-func docutils literal notranslate">PyType_Ready()</code></a> on the new type.
<div class="versionadded">
New in version 3.9.
</div>
<div class="versionchanged">
Changed in version 3.10: The function now accepts a single class as the bases argument and
<code class="docutils literal notranslate">NULL</code> as the <code class="docutils literal notranslate">tp_doc</code> slot.
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_FromSpecWithBases">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *PyType_FromSpecWithBases(<a class="reference internal" href="#c.PyType_Spec" title="PyType_Spec">PyType_Spec</a> *spec, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *bases)<a class="headerlink" href="#c.PyType_FromSpecWithBases" title="Permalink to this definition">¶</a> </dt>
<dd>Return value: New reference. Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a> since version 3.3.Equivalent to <code class="docutils literal notranslate">PyType_FromModuleAndSpec(NULL, spec, bases)</code>.
<div class="versionadded">
New in version 3.3.
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_FromSpec">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> *PyType_FromSpec(<a class="reference internal" href="#c.PyType_Spec" title="PyType_Spec">PyType_Spec</a> *spec)<a class="headerlink" href="#c.PyType_FromSpec" title="Permalink to this definition">¶</a> </dt>
<dd>Return value: New reference. Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a>.Equivalent to <code class="docutils literal notranslate">PyType_FromSpecWithBases(spec, NULL)</code>.
</dd></dl>

<dl class="c type">
<dt class="sig sig-object c" id="c.PyType_Spec">
type PyType_Spec<a class="headerlink" href="#c.PyType_Spec" title="Permalink to this definition">¶</a> </dt>
<dd> Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a> (including all members).Structure defining a type’s behavior.
<dl class="c member">
<dt class="sig sig-object c" id="c.PyType_Spec.PyType_Spec.name">
const char *PyType_Spec.name<a class="headerlink" href="#c.PyType_Spec.PyType_Spec.name" title="Permalink to this definition">¶</a> </dt>
<dd>Name of the type, used to set <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_name" title="PyTypeObject.tp_name"><code class="xref c c-member docutils literal notranslate">PyTypeObject.tp_name</code></a>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyType_Spec.PyType_Spec.basicsize">
int PyType_Spec.basicsize<a class="headerlink" href="#c.PyType_Spec.PyType_Spec.basicsize" title="Permalink to this definition">¶</a> </dt>
<dd></dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyType_Spec.PyType_Spec.itemsize">
int PyType_Spec.itemsize<a class="headerlink" href="#c.PyType_Spec.PyType_Spec.itemsize" title="Permalink to this definition">¶</a> </dt>
<dd>Size of the instance in bytes, used to set
<a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_basicsize" title="PyTypeObject.tp_basicsize"><code class="xref c c-member docutils literal notranslate">PyTypeObject.tp_basicsize</code></a> and
<a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_itemsize" title="PyTypeObject.tp_itemsize"><code class="xref c c-member docutils literal notranslate">PyTypeObject.tp_itemsize</code></a>.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyType_Spec.PyType_Spec.flags">
int PyType_Spec.flags<a class="headerlink" href="#c.PyType_Spec.PyType_Spec.flags" title="Permalink to this definition">¶</a> </dt>
<dd>Type flags, used to set <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_flags" title="PyTypeObject.tp_flags"><code class="xref c c-member docutils literal notranslate">PyTypeObject.tp_flags</code></a>.
If the <code class="docutils literal notranslate">Py_TPFLAGS_HEAPTYPE</code> flag is not set,
<a class="reference internal" href="#c.PyType_FromSpecWithBases" title="PyType_FromSpecWithBases"><code class="xref c c-func docutils literal notranslate">PyType_FromSpecWithBases()</code></a> sets it automatically.
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyType_Spec.PyType_Spec.slots">
<a class="reference internal" href="#c.PyType_Slot" title="PyType_Slot">PyType_Slot</a> *PyType_Spec.slots<a class="headerlink" href="#c.PyType_Spec.PyType_Spec.slots" title="Permalink to this definition">¶</a> </dt>
<dd>Array of <a class="reference internal" href="#c.PyType_Slot" title="PyType_Slot"><code class="xref c c-type docutils literal notranslate">PyType_Slot</code></a> structures.
Terminated by the special slot value <code class="docutils literal notranslate">{0, NULL}</code>.
</dd></dl>

</dd></dl>

<dl class="c type">
<dt class="sig sig-object c" id="c.PyType_Slot">
type PyType_Slot<a class="headerlink" href="#c.PyType_Slot" title="Permalink to this definition">¶</a> </dt>
<dd> Part of the <a class="reference internal" href="stable.html#stable">Stable ABI</a> (including all members).Structure defining optional functionality of a type, containing a slot ID
and a value pointer.
<dl class="c member">
<dt class="sig sig-object c" id="c.PyType_Slot.PyType_Slot.slot">
int PyType_Slot.slot<a class="headerlink" href="#c.PyType_Slot.PyType_Slot.slot" title="Permalink to this definition">¶</a> </dt>
<dd><blockquote>
<div>A slot ID.
Slot IDs are named like the field names of the structures
<a class="reference internal" href="#c.PyTypeObject" title="PyTypeObject"><code class="xref c c-type docutils literal notranslate">PyTypeObject</code></a>, <a class="reference internal" href="typeobj.html#c.PyNumberMethods" title="PyNumberMethods"><code class="xref c c-type docutils literal notranslate">PyNumberMethods</code></a>,
<a class="reference internal" href="typeobj.html#c.PySequenceMethods" title="PySequenceMethods"><code class="xref c c-type docutils literal notranslate">PySequenceMethods</code></a>, <a class="reference internal" href="typeobj.html#c.PyMappingMethods" title="PyMappingMethods"><code class="xref c c-type docutils literal notranslate">PyMappingMethods</code></a> and
<a class="reference internal" href="typeobj.html#c.PyAsyncMethods" title="PyAsyncMethods"><code class="xref c c-type docutils literal notranslate">PyAsyncMethods</code></a> with an added <code class="docutils literal notranslate">Py_</code> prefix.
For example, use:
<ul class="simple">
<li><code class="docutils literal notranslate">Py_tp_dealloc</code> to set <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_dealloc" title="PyTypeObject.tp_dealloc"><code class="xref c c-member docutils literal notranslate">PyTypeObject.tp_dealloc</code></a></li>
<li><code class="docutils literal notranslate">Py_nb_add</code> to set <a class="reference internal" href="typeobj.html#c.PyNumberMethods.nb_add" title="PyNumberMethods.nb_add"><code class="xref c c-member docutils literal notranslate">PyNumberMethods.nb_add</code></a></li>
<li><code class="docutils literal notranslate">Py_sq_length</code> to set <a class="reference internal" href="typeobj.html#c.PySequenceMethods.sq_length" title="PySequenceMethods.sq_length"><code class="xref c c-member docutils literal notranslate">PySequenceMethods.sq_length</code></a></li>
</ul>
The following fields cannot be set at all using <a class="reference internal" href="#c.PyType_Spec" title="PyType_Spec"><code class="xref c c-type docutils literal notranslate">PyType_Spec</code></a> and
<code class="xref c c-type docutils literal notranslate">PyType_Slot</code>:
<ul class="simple">
<li><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_dict" title="PyTypeObject.tp_dict"><code class="xref c c-member docutils literal notranslate">tp_dict</code></a></li>
<li><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_mro" title="PyTypeObject.tp_mro"><code class="xref c c-member docutils literal notranslate">tp_mro</code></a></li>
<li><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_cache" title="PyTypeObject.tp_cache"><code class="xref c c-member docutils literal notranslate">tp_cache</code></a></li>
<li><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_subclasses" title="PyTypeObject.tp_subclasses"><code class="xref c c-member docutils literal notranslate">tp_subclasses</code></a></li>
<li><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_weaklist" title="PyTypeObject.tp_weaklist"><code class="xref c c-member docutils literal notranslate">tp_weaklist</code></a></li>
<li><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_vectorcall" title="PyTypeObject.tp_vectorcall"><code class="xref c c-member docutils literal notranslate">tp_vectorcall</code></a></li>
<li><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_weaklistoffset" title="PyTypeObject.tp_weaklistoffset"><code class="xref c c-member docutils literal notranslate">tp_weaklistoffset</code></a>
(see <a class="reference internal" href="structures.html#pymemberdef-offsets">PyMemberDef</a>)</li>
<li><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_dictoffset" title="PyTypeObject.tp_dictoffset"><code class="xref c c-member docutils literal notranslate">tp_dictoffset</code></a>
(see <a class="reference internal" href="structures.html#pymemberdef-offsets">PyMemberDef</a>)</li>
<li><a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_vectorcall_offset" title="PyTypeObject.tp_vectorcall_offset"><code class="xref c c-member docutils literal notranslate">tp_vectorcall_offset</code></a>
(see <a class="reference internal" href="structures.html#pymemberdef-offsets">PyMemberDef</a>)</li>
</ul>
The following fields cannot be set using <a class="reference internal" href="#c.PyType_Spec" title="PyType_Spec"><code class="xref c c-type docutils literal notranslate">PyType_Spec</code></a> and
<code class="xref c c-type docutils literal notranslate">PyType_Slot</code> under the limited API:
<ul class="simple">
<li><a class="reference internal" href="typeobj.html#c.PyBufferProcs.bf_getbuffer" title="PyBufferProcs.bf_getbuffer"><code class="xref c c-member docutils literal notranslate">bf_getbuffer</code></a></li>
<li><a class="reference internal" href="typeobj.html#c.PyBufferProcs.bf_releasebuffer" title="PyBufferProcs.bf_releasebuffer"><code class="xref c c-member docutils literal notranslate">bf_releasebuffer</code></a></li>
</ul>
Setting <code class="xref c c-data docutils literal notranslate">Py_tp_bases</code> or <code class="xref c c-data docutils literal notranslate">Py_tp_base</code> may be
problematic on some platforms.
To avoid issues, use the bases argument of
<code class="xref py py-func docutils literal notranslate">PyType_FromSpecWithBases()</code> instead.
</div></blockquote>
<div class="versionchanged">
Changed in version 3.9: Slots in <a class="reference internal" href="typeobj.html#c.PyBufferProcs" title="PyBufferProcs"><code class="xref c c-type docutils literal notranslate">PyBufferProcs</code></a> may be set in the unlimited API.
</div>
</dd></dl>

<dl class="c member">
<dt class="sig sig-object c" id="c.PyType_Slot.PyType_Slot.pfunc">
void *PyType_Slot.pfunc<a class="headerlink" href="#c.PyType_Slot.PyType_Slot.pfunc" title="Permalink to this definition">¶</a> </dt>
<dd>The desired value of the slot. In most cases, this is a pointer
to a function.
Slots other than <code class="docutils literal notranslate">Py_tp_doc</code> may not be <code class="docutils literal notranslate">NULL</code>.
</dd></dl>

</dd></dl>

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