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.
Warning
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).
Changed in version 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's 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.
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 a
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 EOFError is
raised if the end of the file is reached immediately.
int PyFile_WriteObject(PyObject *obj, PyObject *p, int flags)
Write object obj to file object p. The only supported flag for flags is
Py_PRINT_RAW; if given, the str() of the object is written
instead of the repr(). Return 0 on success or -1 on failure; the
appropriate exception will be set.
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.