Python’s built-in file objects are implemented entirely on the
FILE*
support from the C standard library. This is an implementation detail and may change in future releases of Python.
PyFile_Type
¶
此实例的
PyTypeObject
represents the Python file type. This is exposed to Python programs as
file
and
types.FileType
.
PyFile_Check
(
PyObject
*p
)
¶
返回 True 若其自变量是
PyFileObject
或子类型的
PyFileObject
.
2.2 版改变： Allowed subtypes to be accepted.
PyFile_CheckExact
(
PyObject
*p
)
¶
返回 True 若其自变量是
PyFileObject
，但不是子类型的
PyFileObject
.
2.2 版新增。
PyFile_FromString
(
char
*filename
, char
*mode
)
¶
On success, return a new file object that is opened on the file given by
filename
, with a file mode given by
mode
，其中
mode
has the same semantics as the standard C routine
fopen()
. On failure, return
NULL
.
PyFile_FromFile
(
FILE
*fp
, char
*name
, char
*mode
, int (
*close
)(FILE*)
)
¶
创建新的
PyFileObject
from the already-open standard C file pointer,
fp
. The function
close
will be called when the file should be closed. Return
NULL
and close the file using
close
当故障时。
close
is optional and can be set to
NULL
.
PyFile_AsFile
(
PyObject
*p
)
¶
Return the file object associated with
p
作为
FILE*
.
If the caller will ever use the returned
FILE*
object while the
GIL
is released it must also call the
PyFile_IncUseCount()
and
PyFile_DecUseCount()
functions described below as appropriate.
PyFile_IncUseCount
(
PyFileObject
*p
)
¶
Increments the PyFileObject’s internal use count to indicate that the underlying
FILE*
is being used. This prevents Python from calling f_close() on it from another thread. Callers of this must call
PyFile_DecUseCount()
when they are finished with the
FILE*
. Otherwise the file object will never be closed by Python.
The GIL must be held while calling this function.
The suggested use is to call this after
PyFile_AsFile()
and before you release the GIL:
FILE *fp = PyFile_AsFile(p); PyFile_IncUseCount(p); /* ... */ Py_BEGIN_ALLOW_THREADS do_something(fp); Py_END_ALLOW_THREADS /* ... */ PyFile_DecUseCount(p);
2.6 版新增。
PyFile_DecUseCount
(
PyFileObject
*p
)
¶
Decrements the PyFileObject’s internal unlocked_count member to indicate that the caller is done with its own use of the
FILE*
. This may only be called to undo a prior call to
PyFile_IncUseCount()
.
The GIL must be held while calling this function (see the example above).
2.6 版新增。
PyFile_GetLine
(
PyObject
*p
, int
n
)
¶
相当于
p.readline([n])
, this function reads one line from the object
p
.
p
may be a file object or any object with a
readline()
方法。若
n
is
0
, exactly one line is read, regardless of the length of the line. If
n
大于
0
, no more than
n
bytes will be read from the file; a partial line can be returned. In both cases, an empty string is returned if the end of the file is reached immediately. If
n
小于
0
, however, one line is read regardless of length, but
EOFError
is raised if the end of the file is reached immediately.
PyFile_Name
(
PyObject
*p
)
¶
Return the name of the file specified by p as a string object.
PyFile_SetBufSize
(
PyFileObject
*p
, int
n
)
¶
Available on systems with
setvbuf()
only. This should only be called immediately after file object creation.
PyFile_SetEncoding
(
PyFileObject
*p
, const char
*enc
)
¶
Set the file’s encoding for Unicode output to
enc
。返回
1
on success and
0
当故障时。
2.3 版新增。
PyFile_SetEncodingAndErrors
(
PyFileObject
*p
, const char
*enc
, *errors
)
¶
Set the file’s encoding for Unicode output to
enc
, and its error mode to
err
。返回
1
on success and
0
当故障时。
2.6 版新增。
PyFile_SoftSpace
(
PyObject
*p
, int
newflag
)
¶
This function exists for internal use by the interpreter. Set the
softspace
attribute of
p
to
newflag
并返回先前值。
p
does not have to be a file object for this function to work properly; any object is supported (thought its only interesting if the
softspace
attribute can be set). This function clears any errors, and will return
0
as the previous value if the attribute either does not exist or if there were errors in retrieving it. There is no way to detect errors from this function, but doing so should not be needed.