File Objects¶
These APIs are a minimal emulation of the Python 2 C API for built-in file
objects, which used to rely on the buffered I/O (FILE*
) support
from the C standard library. In Python 3, files and streams use the new
io
module, which defines several layers over the low-level unbuffered
I/O of the operating system. The functions described below are
convenience C wrappers over these new APIs, and meant mostly for internal
error reporting in the interpreter; third-party code is advised to access
the io
APIs instead.
-
PyFile_FromFd
(int fd, const char *name, const char *mode, int buffering, const char *encoding, const char *errors, const char *newline, int closefd)¶ Create a Python file object 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. name is ignored and kept for backward compatibility. Return NULL on failure. For a more comprehensive description of the arguments, please refer to the
io.open()
function documentation.Advertencia
Since Python streams have their own buffering layer, mixing them with OS-level file descriptors can produce various issues (such as unexpected ordering of data).
Distinto en la versión 3.2: Ignore name attribute.
-
int
PyObject_AsFileDescriptor
(PyObject *p)¶ Return the file descriptor associated with p as an
int
. If the object is an integer, its value is returned. If not, the object’sfileno()
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.
-
PyObject*
PyFile_GetLine
(PyObject *p, int n)¶ - Return value: New reference.
Equivalent to
p.readline([n])
, this function reads one line from the object p. p may be a file object or any object with areadline()
method. If n is0
, exactly one line is read, regardless of the length of the line. If n is greater than0
, 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 than0
, however, one line is read regardless of length, butEOFError
is raised if the end of the file is reached immediately.