String/Bytes Objects¶
These functions raise TypeError
when expecting a string parameter and are
called with a non-string parameter.
注解
These functions have been renamed to PyBytes_* in Python 3.x. Unless otherwise noted, the PyBytes functions available in 3.x are aliased to their PyString_* equivalents to help porting.
-
PyTypeObject
PyString_Type
¶ This instance of
PyTypeObject
represents the Python string type; it is the same object asstr
andtypes.StringType
in the Python layer. .
-
int
PyString_Check
(PyObject *o)¶ Return true if the object o is a string object or an instance of a subtype of the string type.
在 2.2 版更改: Allowed subtypes to be accepted.
-
int
PyString_CheckExact
(PyObject *o)¶ Return true if the object o is a string object, but not an instance of a subtype of the string type.
2.2 新版功能.
-
PyObject*
PyString_FromString
(const char *v)¶ - Return value: New reference.
Return a new string object with a copy of the string v as value on success, and NULL on failure. The parameter v must not be NULL; it will not be checked.
-
PyObject*
PyString_FromStringAndSize
(const char *v, Py_ssize_t len)¶ - Return value: New reference.
Return a new string object with a copy of the string v as value and length len on success, and NULL on failure. If v is NULL, the contents of the string are uninitialized.
在 2.5 版更改: This function used an
int
type for len. This might require changes in your code for properly supporting 64-bit systems.
-
PyObject*
PyString_FromFormat
(const char *format, ...)¶ - Return value: New reference.
Take a C
printf()
-style format string and a variable number of arguments, calculate the size of the resulting Python string and return a string with the values formatted into it. The variable arguments must be C types and must correspond exactly to the format characters in the format string. The following format characters are allowed:Format Characters
Type
Comment
%%
n/a
The literal % character.
%c
int
A single character, represented as a C int.
%d
int
Exactly equivalent to
printf("%d")
.%u
unsigned int
Exactly equivalent to
printf("%u")
.%ld
long
Exactly equivalent to
printf("%ld")
.%lu
unsigned long
Exactly equivalent to
printf("%lu")
.%lld
long long
Exactly equivalent to
printf("%lld")
.%llu
unsigned long long
Exactly equivalent to
printf("%llu")
.%zd
Py_ssize_t
Exactly equivalent to
printf("%zd")
.%zu
size_t
Exactly equivalent to
printf("%zu")
.%i
int
Exactly equivalent to
printf("%i")
.%x
int
Exactly equivalent to
printf("%x")
.%s
char*
A null-terminated C character array.
%p
void*
The hex representation of a C pointer. Mostly equivalent to
printf("%p")
except that it is guaranteed to start with the literal0x
regardless of what the platform’sprintf
yields.An unrecognized format character causes all the rest of the format string to be copied as-is to the result string, and any extra arguments discarded.
注解
The “%lld” and “%llu” format specifiers are only available when
HAVE_LONG_LONG
is defined.在 2.7 版更改: Support for “%lld” and “%llu” added.
-
PyObject*
PyString_FromFormatV
(const char *format, va_list vargs)¶ - Return value: New reference.
Identical to
PyString_FromFormat()
except that it takes exactly two arguments.
-
Py_ssize_t
PyString_Size
(PyObject *string)¶ Return the length of the string in string object string.
在 2.5 版更改: This function returned an
int
type. This might require changes in your code for properly supporting 64-bit systems.
-
Py_ssize_t
PyString_GET_SIZE
(PyObject *string)¶ Macro form of
PyString_Size()
but without error checking.在 2.5 版更改: This macro returned an
int
type. This might require changes in your code for properly supporting 64-bit systems.
-
char*
PyString_AsString
(PyObject *string)¶ Return a NUL-terminated representation of the contents of string. The pointer refers to the internal buffer of string, not a copy. The data must not be modified in any way, unless the string was just created using
PyString_FromStringAndSize(NULL, size)
. It must not be deallocated. If string is a Unicode object, this function computes the default encoding of string and operates on that. If string is not a string object at all,PyString_AsString()
returns NULL and raisesTypeError
.
-
char*
PyString_AS_STRING
(PyObject *string)¶ Macro form of
PyString_AsString()
but without error checking. Only string objects are supported; no Unicode objects should be passed.
-
int
PyString_AsStringAndSize
(PyObject *obj, char **buffer, Py_ssize_t *length)¶ Return a NUL-terminated representation of the contents of the object obj through the output variables buffer and length.
The function accepts both string and Unicode objects as input. For Unicode objects it returns the default encoded version of the object. If length is NULL, the resulting buffer may not contain NUL characters; if it does, the function returns
-1
and aTypeError
is raised.The buffer refers to an internal string buffer of obj, not a copy. The data must not be modified in any way, unless the string was just created using
PyString_FromStringAndSize(NULL, size)
. It must not be deallocated. If string is a Unicode object, this function computes the default encoding of string and operates on that. If string is not a string object at all,PyString_AsStringAndSize()
returns-1
and raisesTypeError
.在 2.5 版更改: This function used an
int *
type for length. This might require changes in your code for properly supporting 64-bit systems.
-
void
PyString_Concat
(PyObject **string, PyObject *newpart)¶ Create a new string object in *string containing the contents of newpart appended to string; the caller will own the new reference. The reference to the old value of string will be stolen. If the new string cannot be created, the old reference to string will still be discarded and the value of *string will be set to NULL; the appropriate exception will be set.
-
void
PyString_ConcatAndDel
(PyObject **string, PyObject *newpart)¶ Create a new string object in *string containing the contents of newpart appended to string. This version decrements the reference count of newpart.
-
int
_PyString_Resize
(PyObject **string, Py_ssize_t newsize)¶ A way to resize a string object even though it is “immutable”. Only use this to build up a brand new string object; don’t use this if the string may already be known in other parts of the code. It is an error to call this function if the refcount on the input string object is not one. Pass the address of an existing string object as an lvalue (it may be written into), and the new size desired. On success, *string holds the resized string object and
0
is returned; the address in *string may differ from its input value. If the reallocation fails, the original string object at *string is deallocated, *string is set to NULL, a memory exception is set, and-1
is returned.在 2.5 版更改: This function used an
int
type for newsize. This might require changes in your code for properly supporting 64-bit systems.
-
PyObject*
PyString_Format
(PyObject *format, PyObject *args)¶ - Return value: New reference.
Return a new string object from format and args. Analogous to
format % args
. The args argument must be a tuple or dict.
-
void
PyString_InternInPlace
(PyObject **string)¶ Intern the argument *string in place. The argument must be the address of a pointer variable pointing to a Python string object. If there is an existing interned string that is the same as *string, it sets *string to it (decrementing the reference count of the old string object and incrementing the reference count of the interned string object), otherwise it leaves *string alone and interns it (incrementing its reference count). (Clarification: even though there is a lot of talk about reference counts, think of this function as reference-count-neutral; you own the object after the call if and only if you owned it before the call.)
注解
This function is not available in 3.x and does not have a PyBytes alias.
-
PyObject*
PyString_InternFromString
(const char *v)¶ - Return value: New reference.
A combination of
PyString_FromString()
andPyString_InternInPlace()
, returning either a new string object that has been interned, or a new (“owned”) reference to an earlier interned string object with the same value.注解
This function is not available in 3.x and does not have a PyBytes alias.
-
PyObject*
PyString_Decode
(const char *s, Py_ssize_t size, const char *encoding, const char *errors)¶ - Return value: New reference.
Create an object by decoding size bytes of the encoded buffer s using the codec registered for encoding. encoding and errors have the same meaning as the parameters of the same name in the
unicode()
built-in function. The codec to be used is looked up using the Python codec registry. Return NULL if an exception was raised by the codec.注解
This function is not available in 3.x and does not have a PyBytes alias.
在 2.5 版更改: This function used an
int
type for size. This might require changes in your code for properly supporting 64-bit systems.
-
PyObject*
PyString_AsDecodedObject
(PyObject *str, const char *encoding, const char *errors)¶ - Return value: New reference.
Decode a string object by passing it to the codec registered for encoding and return the result as Python object. encoding and errors have the same meaning as the parameters of the same name in the string
encode()
method. The codec to be used is looked up using the Python codec registry. Return NULL if an exception was raised by the codec.注解
This function is not available in 3.x and does not have a PyBytes alias.
-
PyObject*
PyString_Encode
(const char *s, Py_ssize_t size, const char *encoding, const char *errors)¶ - Return value: New reference.
Encode the
char
buffer of the given size by passing it to the codec registered for encoding and return a Python object. encoding and errors have the same meaning as the parameters of the same name in the stringencode()
method. The codec to be used is looked up using the Python codec registry. Return NULL if an exception was raised by the codec.注解
This function is not available in 3.x and does not have a PyBytes alias.
在 2.5 版更改: This function used an
int
type for size. This might require changes in your code for properly supporting 64-bit systems.
-
PyObject*
PyString_AsEncodedObject
(PyObject *str, const char *encoding, const char *errors)¶ - Return value: New reference.
Encode a string object using the codec registered for encoding and return the result as Python object. encoding and errors have the same meaning as the parameters of the same name in the string
encode()
method. The codec to be used is looked up using the Python codec registry. Return NULL if an exception was raised by the codec.注解
This function is not available in 3.x and does not have a PyBytes alias.