### 导航 - [索引](../genindex.xhtml "总目录") - [模块](../py-modindex.xhtml "Python 模块索引") | - [下一页](mapping.xhtml "Mapping Protocol") | - [上一页](number.xhtml "数字协议") | -  - [Python](https://www.python.org/) » - zh\_CN 3.7.3 [文档](../index.xhtml) » - [Python/C API 参考手册](index.xhtml) » - [抽象对象层](abstract.xhtml) » - $('.inline-search').show(0); | # Sequence Protocol int `PySequence_Check`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*)Return `1` if the object provides sequence protocol, and `0` otherwise. Note that it returns `1` for Python classes with a [`__getitem__()`](../reference/datamodel.xhtml#object.__getitem__ "object.__getitem__")method unless they are [`dict`](../library/stdtypes.xhtml#dict "dict") subclasses since in general case it is impossible to determine what the type of keys it supports. This function always succeeds. Py\_ssize\_t `PySequence_Size`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*)Py\_ssize\_t `PySequence_Length`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*)Returns the number of objects in sequence *o* on success, and `-1` on failure. This is equivalent to the Python expression `len(o)`. [PyObject](structures.xhtml#c.PyObject "PyObject")\* `PySequence_Concat`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o1*, [PyObject](structures.xhtml#c.PyObject "PyObject") *\*o2*)*Return value: New reference.*Return the concatenation of *o1* and *o2* on success, and *NULL* on failure. This is the equivalent of the Python expression `o1 + o2`. [PyObject](structures.xhtml#c.PyObject "PyObject")\* `PySequence_Repeat`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*, Py\_ssize\_t *count*)*Return value: New reference.*Return the result of repeating sequence object *o* *count* times, or *NULL* on failure. This is the equivalent of the Python expression `o * count`. [PyObject](structures.xhtml#c.PyObject "PyObject")\* `PySequence_InPlaceConcat`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o1*, [PyObject](structures.xhtml#c.PyObject "PyObject") *\*o2*)*Return value: New reference.*Return the concatenation of *o1* and *o2* on success, and *NULL* on failure. The operation is done *in-place* when *o1* supports it. This is the equivalent of the Python expression `o1 += o2`. [PyObject](structures.xhtml#c.PyObject "PyObject")\* `PySequence_InPlaceRepeat`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*, Py\_ssize\_t *count*)*Return value: New reference.*Return the result of repeating sequence object *o* *count* times, or *NULL* on failure. The operation is done *in-place* when *o* supports it. This is the equivalent of the Python expression `o *= count`. [PyObject](structures.xhtml#c.PyObject "PyObject")\* `PySequence_GetItem`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*, Py\_ssize\_t *i*)*Return value: New reference.*Return the *i*th element of *o*, or *NULL* on failure. This is the equivalent of the Python expression `o[i]`. [PyObject](structures.xhtml#c.PyObject "PyObject")\* `PySequence_GetSlice`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*, Py\_ssize\_t *i1*, Py\_ssize\_t *i2*)*Return value: New reference.*Return the slice of sequence object *o* between *i1* and *i2*, or *NULL* on failure. This is the equivalent of the Python expression `o[i1:i2]`. int `PySequence_SetItem`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*, Py\_ssize\_t *i*, [PyObject](structures.xhtml#c.PyObject "PyObject") *\*v*)Assign object *v* to the *i*th element of *o*. Raise an exception and return `-1` on failure; return `0` on success. This is the equivalent of the Python statement `o[i] = v`. This function *does not* steal a reference to *v*. If *v* is *NULL*, the element is deleted, however this feature is deprecated in favour of using [`PySequence_DelItem()`](#c.PySequence_DelItem "PySequence_DelItem"). int `PySequence_DelItem`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*, Py\_ssize\_t *i*)Delete the *i*th element of object *o*. Returns `-1` on failure. This is the equivalent of the Python statement `del o[i]`. int `PySequence_SetSlice`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*, Py\_ssize\_t *i1*, Py\_ssize\_t *i2*, [PyObject](structures.xhtml#c.PyObject "PyObject") *\*v*)Assign the sequence object *v* to the slice in sequence object *o* from *i1* to *i2*. This is the equivalent of the Python statement `o[i1:i2] = v`. int `PySequence_DelSlice`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*, Py\_ssize\_t *i1*, Py\_ssize\_t *i2*)Delete the slice in sequence object *o* from *i1* to *i2*. Returns `-1` on failure. This is the equivalent of the Python statement `del o[i1:i2]`. Py\_ssize\_t `PySequence_Count`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*, [PyObject](structures.xhtml#c.PyObject "PyObject") *\*value*)Return the number of occurrences of *value* in *o*, that is, return the number of keys for which `o[key] == value`. On failure, return `-1`. This is equivalent to the Python expression `o.count(value)`. int `PySequence_Contains`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*, [PyObject](structures.xhtml#c.PyObject "PyObject") *\*value*)Determine if *o* contains *value*. If an item in *o* is equal to *value*, return `1`, otherwise return `0`. On error, return `-1`. This is equivalent to the Python expression `value in o`. Py\_ssize\_t `PySequence_Index`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*, [PyObject](structures.xhtml#c.PyObject "PyObject") *\*value*)Return the first index *i* for which `o[i] == value`. On error, return `-1`. This is equivalent to the Python expression `o.index(value)`. [PyObject](structures.xhtml#c.PyObject "PyObject")\* `PySequence_List`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*)*Return value: New reference.*Return a list object with the same contents as the sequence or iterable *o*, or *NULL* on failure. The returned list is guaranteed to be new. This is equivalent to the Python expression `list(o)`. [PyObject](structures.xhtml#c.PyObject "PyObject")\* `PySequence_Tuple`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*)*Return value: New reference.*Return a tuple object with the same contents as the sequence or iterable *o*, or *NULL* on failure. If *o* is a tuple, a new reference will be returned, otherwise a tuple will be constructed with the appropriate contents. This is equivalent to the Python expression `tuple(o)`. [PyObject](structures.xhtml#c.PyObject "PyObject")\* `PySequence_Fast`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*, const char *\*m*)*Return value: New reference.*Return the sequence or iterable *o* as a list, unless it is already a tuple or list, in which case *o* is returned. Use [`PySequence_Fast_GET_ITEM()`](#c.PySequence_Fast_GET_ITEM "PySequence_Fast_GET_ITEM") to access the members of the result. Returns *NULL* on failure. If the object is not a sequence or iterable, raises [`TypeError`](../library/exceptions.xhtml#TypeError "TypeError") with *m* as the message text. Py\_ssize\_t `PySequence_Fast_GET_SIZE`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*)Returns the length of *o*, assuming that *o* was returned by [`PySequence_Fast()`](#c.PySequence_Fast "PySequence_Fast") and that *o* is not *NULL*. The size can also be gotten by calling [`PySequence_Size()`](#c.PySequence_Size "PySequence_Size") on *o*, but [`PySequence_Fast_GET_SIZE()`](#c.PySequence_Fast_GET_SIZE "PySequence_Fast_GET_SIZE") is faster because it can assume *o* is a list or tuple. [PyObject](structures.xhtml#c.PyObject "PyObject")\* `PySequence_Fast_GET_ITEM`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*, Py\_ssize\_t *i*)*Return value: Borrowed reference.*Return the *i*th element of *o*, assuming that *o* was returned by [`PySequence_Fast()`](#c.PySequence_Fast "PySequence_Fast"), *o* is not *NULL*, and that *i* is within bounds. [PyObject](structures.xhtml#c.PyObject "PyObject")\*\* `PySequence_Fast_ITEMS`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*)Return the underlying array of PyObject pointers. Assumes that *o* was returned by [`PySequence_Fast()`](#c.PySequence_Fast "PySequence_Fast") and *o* is not *NULL*. Note, if a list gets resized, the reallocation may relocate the items array. So, only use the underlying array pointer in contexts where the sequence cannot change. [PyObject](structures.xhtml#c.PyObject "PyObject")\* `PySequence_ITEM`([PyObject](structures.xhtml#c.PyObject "PyObject") *\*o*, Py\_ssize\_t *i*)*Return value: New reference.*Return the *i*th element of *o* or *NULL* on failure. Macro form of [`PySequence_GetItem()`](#c.PySequence_GetItem "PySequence_GetItem") but without checking that [`PySequence_Check()`](#c.PySequence_Check "PySequence_Check") on *o* is true and without adjustment for negative indices. ### 导航 - [索引](../genindex.xhtml "总目录") - [模块](../py-modindex.xhtml "Python 模块索引") | - [下一页](mapping.xhtml "Mapping Protocol") | - [上一页](number.xhtml "数字协议") | -  - [Python](https://www.python.org/) » - zh\_CN 3.7.3 [文档](../index.xhtml) » - [Python/C API 参考手册](index.xhtml) » - [抽象对象层](abstract.xhtml) » - $('.inline-search').show(0); | © [版权所有](../copyright.xhtml) 2001-2019, Python Software Foundation. Python 软件基金会是一个非盈利组织。 [请捐助。](https://www.python.org/psf/donations/) 最后更新于 5月 21, 2019. [发现了问题](../bugs.xhtml)？ 使用[Sphinx](http://sphinx.pocoo.org/)1.8.4 创建。