mirror of
https://github.com/python/cpython.git
synced 2024-11-29 00:56:12 +01:00
68 lines
2.8 KiB
ReStructuredText
68 lines
2.8 KiB
ReStructuredText
.. highlightlang:: c
|
|
|
|
.. _fileobjects:
|
|
|
|
File Objects
|
|
------------
|
|
|
|
.. index:: object: file
|
|
|
|
Python's built-in file objects are implemented entirely on the :ctype:`FILE\*`
|
|
support from the C standard library. This is an implementation detail and may
|
|
change in future releases of Python. The ``PyFile_`` APIs are a wrapper over
|
|
the :mod:`io` module.
|
|
|
|
|
|
.. cfunction:: PyFile_FromFd(int fd, char *name, char *mode, int buffering, char *encoding, char *errors, char *newline, int closefd)
|
|
|
|
Create a new :ctype:`PyFileObject` from the file descriptor of an already
|
|
opened file *fd*. The arguments *name*, *encoding*, *errors* and *newline*
|
|
can be *NULL* to use the defaults; *buffering* can be *-1* to use the
|
|
default. Return *NULL* on failure. For a more comprehensive description of
|
|
the arguments, please refer to the :func:`io.open` function documentation.
|
|
|
|
.. warning::
|
|
|
|
Take care when you are mixing streams and descriptors! For more
|
|
information, see `the GNU C Library docs
|
|
<http://www.gnu.org/software/libc/manual/html_node/Stream_002fDescriptor-Precautions.html#Stream_002fDescriptor-Precautions>`_.
|
|
|
|
|
|
.. cfunction:: int PyObject_AsFileDescriptor(PyObject *p)
|
|
|
|
Return the file descriptor associated with *p* as an :ctype:`int`. If the
|
|
object is an integer, its value is returned. If not, the
|
|
object's :meth:`fileno` method is called if it exists; the method must return
|
|
an integer, which is returned as the file descriptor value. Sets an
|
|
exception and returns ``-1`` on failure.
|
|
|
|
|
|
.. cfunction:: PyObject* PyFile_GetLine(PyObject *p, int n)
|
|
|
|
.. index:: single: EOFError (built-in exception)
|
|
|
|
Equivalent to ``p.readline([n])``, this function reads one line from the
|
|
object *p*. *p* may be a file object or any object with a :meth:`readline`
|
|
method. If *n* is ``0``, exactly one line is read, regardless of the length of
|
|
the line. If *n* is greater than ``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* is less than
|
|
``0``, however, one line is read regardless of length, but :exc:`EOFError` is
|
|
raised if the end of the file is reached immediately.
|
|
|
|
|
|
.. cfunction:: int PyFile_WriteObject(PyObject *obj, PyObject *p, int flags)
|
|
|
|
.. index:: single: Py_PRINT_RAW
|
|
|
|
Write object *obj* to file object *p*. The only supported flag for *flags* is
|
|
:const:`Py_PRINT_RAW`; if given, the :func:`str` of the object is written
|
|
instead of the :func:`repr`. Return ``0`` on success or ``-1`` on failure; the
|
|
appropriate exception will be set.
|
|
|
|
|
|
.. cfunction:: int PyFile_WriteString(const char *s, PyObject *p)
|
|
|
|
Write string *s* to file object *p*. Return ``0`` on success or ``-1`` on
|
|
failure; the appropriate exception will be set.
|