org.python.modules._io

Class PyIOBase

java.lang.Object

org.python.core.PyObject

org.python.modules._io.PyIOBase

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

PyIOBaseDerived, PyRawIOBase

public class PyIOBase
extends PyObject

The Python module _io._IOBase, on which the io module depends directly.

Implementation note: The code is based heavily on the Jython 2.6-ish _fileio.PyFileIO, the purely Java-accessible IOBase (both Philip Jenvey's work), and the Python implementation in Lib/_pyio. We do not simply delegate to the implementation in org.python.core.io because of the need to override parts of the implementation in Python subclasses. A call to close(), for example, is required to call flush(), but if delegated to the pure Java implementation would not call the version of flush() overridden in a Python sub-class of _io._IOBase. Equally, the use made by PyRawIOBase.read(int) of readinto(bytearray) would not pick up the version of readinto defined in Python.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.python.core.PyObject

PyObject.ConversionException

Field Summary

Fields

Modifier and Type	Field and Description
static String	close_doc
static String	closed_doc
static String	fileno_doc
static String	flush_doc
static String	isatty_doc
static String	readable_doc
static String	readline_doc
static String	readlines_doc
static String	seek_doc
static String	seekable_doc
static String	tell_doc
static String	truncate_doc
static PyType	TYPE
static String	writable_doc
static String	writelines_doc

Method Summary

Methods

Modifier and Type	Method and Description
PyObject	__enter__() Called at the start of a context-managed suite (supporting the with clause).
boolean	__exit__(PyObject type, PyObject value, PyObject traceback) Called at the end of a context-managed suite (supporting the with clause), and will normally close the stream.
PyObject	__iter__() Return an iterator on which next may be repeatedly called to produce (usually) lines from this stream or file.
PyObject	__iternext__() Return the next element of the sequence that this is an iterator for.
void	_checkClosed()
void	_checkClosed(String msg) Raise an error if the underlying IO stream is closed.
void	_checkReadable() Raise an error if the underlying IO stream is not readable.
void	_checkReadable(String msg) Raise an error if the underlying IO stream is not readable.
void	_checkSeekable() Raise an error if the pointer of underlying IO stream is not capable of being positioned.
void	_checkSeekable(String msg) Raise an error if the pointer of underlying IO stream is not capable of being positioned.
void	_checkWritable() Raise an error if the underlying IO stream is not writable.
void	_checkWritable(String msg) Raise an error if the underlying IO stream is not writable.
void	close() Close the stream.
void	closed_readonly(boolean value)
boolean	closed() Is the stream closed against further client operations?
PyStringMap	fastGetDict() xxx implements where meaningful
PyObject	fileno() Return a file descriptor for the stream.
void	flush() Flush write buffers, or no-op for read-only and non-blocking streams.
boolean	isatty() Is the stream known to be an interactive console?
PyObject	next() May be called repeatedly to produce (usually) lines from this stream or file.
boolean	readable() Is the stream readable?
PyObject	readline() Return one line of text (bytes terminates by '\n'), or the whole stream, whichever is shorter.
PyObject	readline(int limit) Return one line of text (bytes terminates by '\n'), or the specified number of bytes, or the whole stream, whichever is shortest.
PyObject	readlines(PyObject hint) Read a stream as a sequence of lines.
long	seek(long pos) Position the read or write pointer at a given byte offset pos relative to the start.
long	seek(long pos, int whence) Position the read or write pointer at a given byte offset pos relative to a position indicated by whence.
boolean	seekable() Is the stream capable of positioning the read/write pointer?
long	tell() Get the current stream position.
long	truncate() Truncate file to size bytes to the current position (as reported by tell()).
long	truncate(long size) Truncate file to size bytes.
boolean	writable() Is the stream writable?
void	writelines(PyObject lines) Write an iterable sequence of strings to the stream.

Methods inherited from class org.python.core.PyObject

__abs__, __add__, __and__, __call__, __call__, __call__, __call__, __call__, __call__, __call__, __call__, __call__, __call__, __call__, __call__, __call__, __call__, __call__, __call__, __cmp__, __coerce__, __coerce_ex__, __complex__, __contains__, __delattr__, __delattr__, __delete__, __delitem__, __delitem__, __delslice__, __delslice__, __dir__, __div__, __divmod__, __eq__, __findattr__, __findattr__, __findattr_ex__, __finditem__, __finditem__, __finditem__, __float__, __floordiv__, __format__, __ge__, __get__, __getattr__, __getattr__, __getitem__, __getitem__, __getnewargs__, __getslice__, __getslice__, __gt__, __hash__, __hex__, __iadd__, __iand__, __idiv__, __idivmod__, __ifloordiv__, __ilshift__, __imod__, __imul__, __index__, __int__, __invert__, __ior__, __ipow__, __irshift__, __isub__, __itruediv__, __ixor__, __le__, __len__, __long__, __lshift__, __lt__, __mod__, __mul__, __ne__, __neg__, __nonzero__, __not__, __oct__, __or__, __pos__, __pow__, __pow__, __radd__, __rand__, __rdiv__, __rdivmod__, __reduce__, __reduce_ex__, __reduce_ex__, __repr__, __rfloordiv__, __rlshift__, __rmod__, __rmul__, __ror__, __rpow__, __rrshift__, __rshift__, __rsub__, __rtruediv__, __rxor__, __set__, __setattr__, __setattr__, __setitem__, __setitem__, __setitem__, __setslice__, __setslice__, __str__, __sub__, __tojava__, __truediv__, __trunc__, __unicode__, __xor__, _add, _and, _callextra, _cmp, _div, _divmod, _doget, _doget, _doset, _eq, _floordiv, _ge, _gt, _iadd, _iand, _idiv, _idivmod, _ifloordiv, _ilshift, _imod, _imul, _in, _ior, _ipow, _irshift, _is, _isnot, _isub, _itruediv, _ixor, _jcall, _jcallexc, _jthrow, _le, _lshift, _lt, _mod, _mul, _ne, _notin, _or, _pow, _rshift, _sub, _truediv, _xor, asDouble, asIndex, asIndex, asInt, asInt, asIterable, asLong, asLong, asName, asName, asString, asString, asStringOrNull, asStringOrNull, bit_length, conjugate, delDict, delType, dispatch__init__, equals, fastGetClass, getDict, getType, hashCode, implementsDescrDelete, implementsDescrGet, implementsDescrSet, invoke, invoke, invoke, invoke, invoke, invoke, isCallable, isDataDescr, isIndex, isMappingType, isNumberType, isSequenceType, noAttributeError, object___subclasshook__, readonlyAttributeError, setDict, setType, toString

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Field Detail

TYPE

public static final PyType TYPE

seek_doc

public static final String seek_doc

See Also:

Constant Field Values

tell_doc

public static final String tell_doc

See Also:

Constant Field Values

truncate_doc

public static final String truncate_doc

See Also:

Constant Field Values

flush_doc

public static final String flush_doc

See Also:

Constant Field Values

close_doc

public static final String close_doc

See Also:

Constant Field Values

closed_doc

public static final String closed_doc

See Also:

Constant Field Values

seekable_doc

public static final String seekable_doc

See Also:

Constant Field Values

readable_doc

public static final String readable_doc

See Also:

Constant Field Values

writable_doc

public static final String writable_doc

See Also:

Constant Field Values

fileno_doc

public static final String fileno_doc

See Also:

Constant Field Values

isatty_doc

public static final String isatty_doc

See Also:

Constant Field Values

readline_doc

public static final String readline_doc

See Also:

Constant Field Values

readlines_doc

public static final String readlines_doc

See Also:

Constant Field Values

writelines_doc

public static final String writelines_doc

See Also:

Constant Field Values

Method Detail

fastGetDict

public PyStringMap fastGetDict()

Description copied from class: PyObject

xxx implements where meaningful

Overrides:

fastGetDict in class PyObject

Returns:

internal object per instance dict or null

seek

public long seek(long pos,
        int whence)

Position the read or write pointer at a given byte offset pos relative to a position indicated by whence.

• If whence=0, the position will be set to pos bytes.
• If whence=1 the position will be set to the current position plus pos.
• If whence=2 the position will be set to the stream size plus pos (and usually pos<=0).

Parameters:

pos - relative to the specified point

whence - 0=from start, 1=from here, 2=from end

Returns:

the new current position

seek

public final long seek(long pos)

Position the read or write pointer at a given byte offset pos relative to the start.

Parameters:

pos - relative to the start

Returns:

the new current position

tell

public long tell()

Get the current stream position.

Returns:

stream position

truncate

public long truncate(long size)

Truncate file to size bytes.

Parameters:

size - requested for stream

Returns:

the new size

truncate

public long truncate()

Truncate file to size bytes to the current position (as reported by tell()).

Returns:

the new size

flush

public void flush()

Flush write buffers, or no-op for read-only and non-blocking streams. Irrespective of the concrete type of the i/o object, locally-buffered write data is written downstream. Whether the downstream in object is also flushed depends upon the specific type of this object.

closed_readonly

public final void closed_readonly(boolean value)

close

public void close()

Close the stream. If closed already, this is a no-op.

seekable

public boolean seekable()
                 throws PyException

Is the stream capable of positioning the read/write pointer?

Returns:

True if may be positioned

Throws:

PyException(ValueError) - if the object is closed to client operations

PyException

_checkSeekable

public void _checkSeekable(String msg)

Raise an error if the pointer of underlying IO stream is not capable of being positioned.

Parameters:

msg - optional custom message

Throws:

PyException(ValueError) - if the object is closed to client operations

PyException(IOError) - if the stream is not capable of being positioned.

_checkSeekable

public final void _checkSeekable()

Raise an error if the pointer of underlying IO stream is not capable of being positioned.

Throws:

PyException(ValueError) - if the object is closed to client operations

PyException(IOError) - if the stream is not capable of being positioned.

readable

public boolean readable()
                 throws PyException

Is the stream readable?

Returns:

true if readable

Throws:

PyException(ValueError) - if the object is closed to client operations

PyException

_checkReadable

public void _checkReadable(String msg)

Raise an error if the underlying IO stream is not readable.

Parameters:

msg - optional custom message

Throws:

PyException(ValueError) - if the object is closed to client operations

PyException(IOError) - if the stream is not readable.

_checkReadable

public final void _checkReadable()

Raise an error if the underlying IO stream is not readable.

Throws:

PyException(ValueError) - if the object is closed to client operations

PyException(IOError) - if the stream is not readable.

writable

public boolean writable()
                 throws PyException

Is the stream writable?

Returns:

true if writable

Throws:

PyException(ValueError) - if the object is closed to client operations

PyException

_checkWritable

public void _checkWritable(String msg)
                    throws PyException

Raise an error if the underlying IO stream is not writable.

Parameters:

msg - optional custom message

Throws:

PyException(ValueError) - if the object is closed to client operations

PyException(IOError) - if the stream is not writable.

PyException

_checkWritable

public final void _checkWritable()
                          throws PyException

Raise an error if the underlying IO stream is not writable.

Throws:

PyException(ValueError) - if the object is closed to client operations

PyException(IOError) - if the stream is not writable.

PyException

closed

public final boolean closed()

Is the stream closed against further client operations?

Returns:

true if closed

_checkClosed

public void _checkClosed(String msg)
                  throws PyException

Raise an error if the underlying IO stream is closed. (Note opposite sense from _checkSeekable(java.lang.String), etc..

Parameters:

msg - optional custom message

Throws:

PyException(ValueError) - if the object is closed to client operations

PyException

_checkClosed

public final void _checkClosed()
                        throws PyException

Throws:

PyException

__enter__

public PyObject __enter__()

Called at the start of a context-managed suite (supporting the with clause).

Returns:

this object

__exit__

public boolean __exit__(PyObject type,
               PyObject value,
               PyObject traceback)

Called at the end of a context-managed suite (supporting the with clause), and will normally close the stream.

Returns:

false

fileno

public PyObject fileno()

Return a file descriptor for the stream. A CPython file descriptor is an int, but this is not the natural choice in Jython, since Java has no such convention of using integers. File descriptors should be passed around opaquely, so their actual type is irrelevant, as long as (say) _io.open(PyObject[], String[]) accepts the type that RawIOBase.fileno() returns.

Returns:

a file descriptor (as opaque object)

isatty

public boolean isatty()

Is the stream known to be an interactive console? This relies on the ability of the underlying stream to know, which is not always possible.

Returns:

true if a console: false if not or we can't tell

readline

public PyObject readline(int limit)

Return one line of text (bytes terminates by '\n'), or the specified number of bytes, or the whole stream, whichever is shortest.

Parameters:

limit - maximum number of bytes (<0 means no limit)

Returns:

the line (or fragment)

readline

public PyObject readline()

Return one line of text (bytes terminates by '\n'), or the whole stream, whichever is shorter.

Returns:

the line (or fragment)

__iter__

public PyObject __iter__()

Return an iterator on which next may be repeatedly called to produce (usually) lines from this stream or file.

Overrides:

__iter__ in class PyObject

__iternext__

public PyObject __iternext__()

Description copied from class: PyObject

Return the next element of the sequence that this is an iterator for. Returns null when the end of the sequence is reached.

Overrides:

__iternext__ in class PyObject

next

public PyObject next()
              throws PyException

May be called repeatedly to produce (usually) lines from this stream or file.

Returns:

next line from the stream or file

Throws:

PyException(StopIteration) - when iteration has reached a natural conclusion

PyException(ValueError) - if the file or stream is closed

PyException(IOError) - reflecting an I/O error in during the read

PyException

readlines

public PyObject readlines(PyObject hint)

Read a stream as a sequence of lines.

Parameters:

hint - stop reading lines after this many bytes (if not EOF first)

Returns:

list containing the lines read

writelines

public void writelines(PyObject lines)

Write an iterable sequence of strings to the stream.

Parameters:

lines -