PyIOBase (Jython API documentation)

java.lang.Object
- org.python.core.PyObject
- - org.python.modules._io.PyIOBase

All Implemented Interfaces:

Serializable, FinalizableBuiltin, Traverseproc

Direct Known Subclasses:

PyIOBaseDerived, PyRawIOBase
```
public class PyIOBase
extends PyObject
implements FinalizableBuiltin, Traverseproc
```
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`

Fields inherited from class org.python.core.PyObject
gcMonitorGlobal

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`__del_builtin__()` `FinalizableBuiltin.__del_builtin__()` is the built-in's own finalizer, while `FinalizablePyObjectDerived.__del_derived__()` refers to an instance's in-dict `__del__`.
`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.
`boolean`	`refersDirectlyTo(PyObject ob)` Optional operation.
`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.
`int`	`traverse(Visitproc visit, Object arg)` Traverses all directly contained `PyObject`s.
`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__, __ensure_finalizer__, __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, isInteger, 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 -
  - __del_builtin__
```
public void __del_builtin__()
```
    Description copied from interface: FinalizableBuiltin
    
    FinalizableBuiltin.__del_builtin__() is the built-in's own finalizer, while FinalizablePyObjectDerived.__del_derived__() refers to an instance's in-dict __del__. A FinalizeTrigger calls FinalizablePyObjectDerived.__del_derived__() first and - if existent - FinalizableBuiltin.__del_builtin__() after that. A plain FinalizablePyObject.__del__() would behave as overwritten by FinalizablePyObjectDerived.__del_derived__(), i.e. won't be called if the type implements FinalizablePyObjectDerived, while FinalizableBuiltin.__del_builtin__() is called in any case.
    
    Specified by:
    
    __del_builtin__ in interface FinalizableBuiltin
  - traverse
```
public int traverse(Visitproc visit,
           Object arg)
```
    Description copied from interface: Traverseproc
    
    Traverses all directly contained PyObjects. Like in CPython, arg must be passed unmodified to visit as its second parameter. If Visitproc.visit(PyObject, Object) returns nonzero, this return value must be returned immediately by traverse. Visitproc.visit(PyObject, Object) must not be called with a null PyObject-argument.
    
    Specified by:
    
    traverse in interface Traverseproc
  - refersDirectlyTo
```
public boolean refersDirectlyTo(PyObject ob)
```
    Description copied from interface: Traverseproc
    
    Optional operation. Should only be implemented if it is more efficient than calling Traverseproc.traverse(Visitproc, Object) with a visitproc that just watches out for ob. Must return false if ob is null.
    
    Specified by:
    
    refersDirectlyTo in interface Traverseproc

Class PyIOBase

Nested Class Summary

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

Field Summary

Fields inherited from class org.python.core.PyObject

Method Summary

Methods inherited from class org.python.core.PyObject

Methods inherited from class java.lang.Object

Field Detail

TYPE

seek_doc

tell_doc

truncate_doc

flush_doc

close_doc

closed_doc

seekable_doc

readable_doc

writable_doc

fileno_doc

isatty_doc

readline_doc

readlines_doc

writelines_doc

Method Detail

fastGetDict

seek

seek

tell

truncate

truncate

flush

closed_readonly

close

seekable

_checkSeekable

_checkSeekable

readable

_checkReadable

_checkReadable

writable

_checkWritable

_checkWritable

closed

_checkClosed

_checkClosed

__enter__

__exit__

fileno

isatty

readline

readline

__iter__

__iternext__

next

readlines

writelines

__del_builtin__

traverse

refersDirectlyTo

enter

exit

iter

iternext