7.5.1 File Objects

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.

PyFileObject: This subtype of PyObject represents a Python file object.

PyTypeObject PyFile_Type: This instance of PyTypeObject represents the Python file type. This is exposed to Python programs as types.FileType.

int PyFile_Check(PyObject *p): Returns true if its argument is a PyFileObject or a subtype of PyFileObject. Changed in version 2.2: Allowed subtypes to be accepted.

int PyFile_CheckExact(PyObject *p): Returns true if its argument is a PyFileObject, but not a subtype of PyFileObject. New in version 2.2.

PyObject* PyFile_FromString(char *filename, char *mode): Return value: New reference.
On success, returns a new file object that is opened on the file given by filename, with a file mode given by mode, where mode has the same semantics as the standard C routine fopen() . On failure, returns NULL.

PyObject* PyFile_FromFile(FILE *fp, char *name, char *mode, int (*close)(FILE*)): Return value: New reference.
Creates a new PyFileObject from the already-open standard C file pointer, fp. The function close will be called when the file should be closed. Returns NULL on failure.

FILE* PyFile_AsFile(PyFileObject *p): Returns the file object associated with p as a FILE*.

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.

PyObject* PyFile_Name(PyObject *p): Return value: Borrowed reference.
Returns the name of the file specified by p as a string object.

void PyFile_SetBufSize(PyFileObject *p, int n): Available on systems with setvbuf() only. This should only be called immediately after file object creation.

int PyFile_SoftSpace(PyObject *p, int newflag): This function exists for internal use by the interpreter. Sets the softspace attribute of p to newflag and returns the previous value. 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.

int PyFile_WriteObject(PyObject *obj, PyFileObject *p, int flags): Writes 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(). Returns 0 on success or -1 on failure; the appropriate exception will be set.

int PyFile_WriteString(const char *s, PyFileObject *p): Writes string s to file object p. Returns 0 on success or -1 on failure; the appropriate exception will be set.

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