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
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)¶
- Return value: New reference.
Create a Python file object from the file descriptor of an already opened file fd. The arguments name, encoding, errors and newline can be
NULLto use the defaults; buffering can be -1 to use the default. name is ignored and kept for backward compatibility. Return
NULLon failure. For a more comprehensive description of the arguments, please refer to the
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.
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
PyFile_GetLine(PyObject *p, int n)¶
- Return value: New reference.
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
EOFErroris raised if the end of the file is reached immediately.
Overrides the normal behavior of
io.open_code()to pass its parameter through the provided handler.
The handler is a function of type PyObject *(*)(PyObject *path, void *userData), where path is guaranteed to be
The userData pointer is passed into the hook function. Since hook functions may be called from different runtimes, this pointer should not refer directly to Python state.
As this hook is intentionally used during import, avoid importing new modules during its execution unless they are known to be frozen or available in
Once a hook has been set, it cannot be removed or replaced, and later calls to
PyFile_SetOpenCodeHook()will fail. On failure, the function returns -1 and sets an exception if the interpreter has been initialized.
This function is safe to call before
Raises an auditing event
setopencodehookwith no arguments.
New in version 3.8.
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
0on success or
-1on failure; the appropriate exception will be set.