documentation/pyserial_api.rst - platform/external/python/pyserial - Gitiles

 ==============
  pySerial API
 ==============

 .. module:: serial

 Classes
 =======

 .. class:: Serial

     .. method:: __init__(port=None, baudrate=9600, bytesize=EIGHTBITS, parity=PARITY_NONE, stopbits=STOPBITS_ONE, timeout=None, xonxoff=0, rtscts=0, interCharTimeout=None)

         :param port:
             Device name or port number number or :const:`None`.

         :param baudrate:
             Baud rate such as 9600 or 115200 etc.

         :param bytesize:
             Number of data bits. Possible values:
             :const:`FIVEBITS`, :const:`SIXBITS`, :const:`SEVENBITS`,
             :const:`EIGHTBITS`

         :param parity:
             Enable parity checking. Possible values:
             :const:`PARITY_NONE` :const:`PARITY_EVEN` :const:`PARITY_ODD`
             :const:`PARITY_MARK` :const:`PARITY_SPACE`

         :param stopbits:
             Number of stop bits. Possible values:
             :const:`STOPBITS_ONE` :const:`STOPBITS_ONE_POINT_FIVE`
             :const:`STOPBITS_TWO`

         :param timeout:
             Set a read timeout value.

         :param xonxoff:
             Enable software flow control.

         :param rtscts:
             Enable hardware (RTS/CTS) flow control.

         :param interCharTimeout:
             Inter-character timeout, :const:`None` to disable (default).

         :exception ValueError:
             Will be raised when parameter are out of range, e.g. baud rate, data bits.

         :exception SerialException:
             In case the device can not be found or can not be configured.


         The port is immediately opened on object creation, when a *port* is
         given. It is not opened when *port* is :const:`None` and a successive call
         to :meth:`open` will be needed.

         Possible values for the parameter *port*:

         - Number: number of device, numbering starts at zero.
         - Device name: depending on operating system. e.g. ``/dev/ttyUSB0``
           on GNU/Linux or ``COM3`` on Windows.

         Possible values for the parameter *timeout*:

         - ``timeout = None``:  wait forever
         - ``timeout = 0``:     non-blocking mode (return immediately on read)
         - ``timeout = x``:     set timeout to ``x`` seconds (float allowed)


     .. method:: open()

         Open port.

     .. method:: close()

         Close port immediately.


     The following methods may raise :exc:`ValueError` when applied to a closed
     port.

     .. method:: read(size=1)

         :param size: Number of bytes to read.
         :return: Bytes read from the port.

         Read *size* bytes from the serial port. If a timeout is set it may
         return less characters as requested. With no timeout it will block
         until the requested number of bytes is read.

         .. versionchanged:: 2.5
             Returns an instance of :class:`bytes` when available (Python 2.6
             and newer) and :class:`str` otherwiese.

     .. method:: write(data)

         :param data: Data to send.
         :return: Number of bytes written.
         :exception SerialTimeoutException:
             In case a write timeout is configured for the port and the time is
             exceeded.

         Write the string *data* to the port.

         .. versionchanged:: 2.5
             Accepts instances of :class:`bytes` and :class:`bytearray` when
             available (Python 2.6 and newer) and :class:`str` otherwiese.

     .. method:: inWaiting()

         Return the number of chars in the receive buffer.

     .. method:: flush()

         Flush of file like objects. In this case, wait until all data is
         written.

     .. method:: flushInput()

         Flush input buffer, discarding all it's contents.

     .. method:: flushOutput()

         Clear output buffer, aborting the current output and
         discarding all that is in the buffer.

     .. method:: sendBreak(duration=0.25)

         :param duration: Time (float) to activate the BREAK condition.

         Send break condition. Timed, returns to idle state after given
         duration.

     .. method:: setBreak(level=True)

         :param level: when true activate BREAK condition, else disable.

         Set break: Controls TXD. When active, no transmitting is possible.

     .. method:: setRTS(level=True)

         :param level: Set control line to logic level.

         Set RTS line to specified logic level.

     .. method:: setDTR(level=True)

         :param level: Set control line to logic level.

         Set DTR line to specified logic level.

     .. method:: getCTS()

         :return: Current state (boolean)

         Return the state of the CTS line.

     .. method:: getDSR()

         :return: Current state (boolean)

         Return the state of the DSR line.

     .. method:: getRI()

         :return: Current state (boolean)

         Return the state of the RI line.

     .. method:: getCD()

         :return: Current state (boolean)

         Return the state of the CD line

     Read-only attributes:

     .. attribute:: name

         Device name. This is always the device name even if the
         port was opened by a number. (Read Only).

         .. versionadded:: 2.5

     .. attribute:: portstr

         :deprecated: use :attr:`name` instead

     .. attribute:: BAUDRATES

         A list of valid baud rates. The list may be incomplete such that higher
         baud rates may be supported by the device and that values in between the
         standard baud rates are supported. (Read Only).

     .. attribute:: BYTESIZES

         A list of valid byte sizes for the device (Read Only).

     .. attribute:: PARITIES

         A list of valid parities for the device (Read Only).

     .. attribute:: STOPBITS

         A list of valid stop bit widths for the device (Read Only).


     New values can be assigned to the following attributes, the port will be
     reconfigured, even if it's opened at that time:

     .. attribute:: port

         Port name/number as set by the user.

     .. attribute:: baudrate

         Current baud rate setting.

     .. attribute:: bytesize

         Byte size in bits.

     .. attribute:: parity

         Parity setting.

     .. attribute:: stopbits

         Stop bit with.

     .. attribute:: timeout

         Timeout setting (seconds, float).

     .. attribute:: xonxoff

         If Xon/Xoff flow control is enabled.

     .. attribute:: rtscts

         If hardware flow control is enabled.

     Platform specific methods.

     .. warning:: Programs using the following methods are not portable to other platforms!

     .. method:: nonblocking()

         :platform: Unix

         Configure the device for nonblocking operations. This can be useful if
         the port is used with ``select``.

     .. method:: fileno()

         :platform: Unix
         :return: File descriptor.

         Return file descriptor number for the port that is opened by this object.

     .. method:: setXON(level=True)

         :platform: Windows
         :param level: Set flow control state.

         Set software flow control state.


 .. class:: SerialBase

     The following attributes are implemented as properties. They work with open
     and closed ports.

     .. attribute:: port

         Read or write port. When the port is already open, it will be closed
         and reopened with the new setting.

     .. attribute:: baudrate

         Read or write current baud rate setting.

     .. attribute:: bytesize

         Read or write current data byte size setting.

     .. attribute:: parity

         Read or write current parity setting.

     .. attribute:: stopbits

         Read or write current stop bit width setting.

     .. attribute:: timeout

         Read or write current read timeout setting.

     .. attribute:: writeTimeout

         Read or write current write timeout setting.

     .. attribute:: xonxoff

         Read or write current software flow control rate setting.

     .. attribute:: rtscts

         Read or write current hardware flow control setting.

     .. attribute:: dsrdtr

         Read or write current hardware flow control setting.

     .. attribute:: interCharTimeout

         Read or write current inter character timeout setting.

     The following constants are also provided:

     .. attribute:: BAUDRATES

         A tuple of standard baud rate values. The actual device may support more
         or less...

     .. attribute:: BYTESIZES

         A tuple of supported byte size values.

     .. attribute:: PARITIES

         A tuple of supported parity settings.

     .. attribute:: STOPBITS

         A tuple of supported stop bit settings.

     .. method:: readline(size=None, eol='\\n')

         :param size: Max number of bytes to read, ``None`` -> no limit.
         :param eol: The end of line character.

         Read a line which is terminated with end-of-line (*eol*) character
         (``\\n`` by default) or until timeout.

     .. method:: readlines(sizehint=None, eol='\\n')

         :param size: Ignored parameter.
         :param eol: The end of line character.

         Read a list of lines, until timeout. *sizehint* is ignored and only
         present for API compatibility with built-in File objects.

     .. method:: xreadlines(sizehint=None)

         Just calls :meth:`readlines` - here for compatibility.

     For compatibility with the :mod:`io` library are the following methods.

     .. method:: readable()

         :return: True
         .. versionadded:: 2.5

     .. method:: writable()

         :return: True
         .. versionadded:: 2.5

     .. method:: seekable()

         :return: False
         .. versionadded:: 2.5

     .. method:: readinto(b)

         :param b: bytearray or array instace
         :return: Number of byte read

         Read up to len(b) bytes into bytearray b and return the number of bytes read.

         .. versionadded:: 2.5


 .. note::

     For systems that provide the :mod:`io` library (Python 2.6 and newer), the
     class :class:`Serial` will derrive from :class:`io.RawIOBase`. For all
     others from :class:`FileLike`.

 .. class:: FileLike

     An abstract file like class. It is used as base class for :class:`Serial`.

     This class implements :meth:`readline` and :meth:`readlines` based on read
     and :meth:`writelines` based on write.  This class is used to provide the
     above functions for to Serial port objects.

     Note that when the serial port was opened with no timeout that
     :meth:`readline` blocks until it sees a newline (or the specified size is
     reached) and that :meth:`readlines` would never return and therefore
     refuses to work (it raises an exception in this case)!

     .. method:: writelines(sequence)

         Write a list of strings to the port.


     The following three methods are overridden in :class:`Serial`.

     .. method:: flush()

         Flush of file like objects. It's a no-op in this class, may be overridden.

     .. method:: read()

         Raises NotImplementedError, needs to be overridden by subclass.

     .. method:: write(data)

         Raises NotImplementedError, needs to be overridden by subclass.

     The following functions are implemented for compatibility with other
     file-like objects, however serial ports are not seekable.


     .. method:: seek(pos, whence=0)

         :exception IOError: always, as method is not supported on serial port

         .. versionadded:: 2.5

     .. method:: tell()

         :exception IOError: always, as method is not supported on serial port

         .. versionadded:: 2.5

     .. method:: truncate(self, n=None)

         :exception IOError: always, as method is not supported on serial port

         .. versionadded:: 2.5

     .. method:: isatty()

         :exception IOError: always, as method is not supported on serial port

         .. versionadded:: 2.5

     To be able to use the file like object as iterator for e.g.
     ``for line in Serial(0): ...`` usage:

     .. method:: next()

         Return the next line by calling :meth:`readline`.

     .. method:: __iter__()

         Returns self.


 Exceptions
 ==========

 .. exception:: SerialException

     Base class for serial port exceptions.

     .. versionchanged:: 2.5
         Now derrives from :exc:`IOError` instead of :exc:`Exception`

 .. exception:: SerialTimeoutException

     Exception that is raised on write timeouts.


 Constants
 =========

 Parity
 ------
 .. data:: PARITY_NONE
 .. data:: PARITY_EVEN
 .. data:: PARITY_ODD
 .. data:: PARITY_MARK
 .. data:: PARITY_SPACE

 Stop bits
 ---------
 .. data:: STOPBITS_ONE
 .. data:: STOPBITS_ONE_POINT_FIVE
 .. data:: STOPBITS_TWO

 Byte size
 ---------
 .. data:: FIVEBITS
 .. data:: SIXBITS
 .. data:: SEVENBITS
 .. data:: EIGHTBITS

 Others
 -------
 Default control characters for software flow control:

 .. data:: XON
 .. data:: XOFF

 Module version:

 .. data:: VERSION

     A string indicating the pySerial version, such as ``2.5``.

 Functions:

 .. function:: device(number)

     :param number: Port number.
     :return: String containing device name.
     :deprecated: Use device names directly.

     Convert a port number to a platform dependent device name. Unfortunately
     this does not work well for all platforms; e.g. some may miss USB-Serial
     converters and enumerate only internal serial ports.

     The conversion may be made off-line, that is, there is no guarantee that
     the returned device name really exists on the system.
	==============
	pySerial API
	==============

	.. module:: serial

	Classes
	=======

	.. class:: Serial

	.. method:: __init__(port=None, baudrate=9600, bytesize=EIGHTBITS, parity=PARITY_NONE, stopbits=STOPBITS_ONE, timeout=None, xonxoff=0, rtscts=0, interCharTimeout=None)

	:param port:
	Device name or port number number or :const:`None`.

	:param baudrate:
	Baud rate such as 9600 or 115200 etc.

	:param bytesize:
	Number of data bits. Possible values:
	:const:`FIVEBITS`, :const:`SIXBITS`, :const:`SEVENBITS`,
	:const:`EIGHTBITS`

	:param parity:
	Enable parity checking. Possible values:
	:const:`PARITY_NONE` :const:`PARITY_EVEN` :const:`PARITY_ODD`
	:const:`PARITY_MARK` :const:`PARITY_SPACE`

	:param stopbits:
	Number of stop bits. Possible values:
	:const:`STOPBITS_ONE` :const:`STOPBITS_ONE_POINT_FIVE`
	:const:`STOPBITS_TWO`

	:param timeout:
	Set a read timeout value.

	:param xonxoff:
	Enable software flow control.

	:param rtscts:
	Enable hardware (RTS/CTS) flow control.

	:param interCharTimeout:
	Inter-character timeout, :const:`None` to disable (default).

	:exception ValueError:
	Will be raised when parameter are out of range, e.g. baud rate, data bits.

	:exception SerialException:
	In case the device can not be found or can not be configured.


	The port is immediately opened on object creation, when a port is
	given. It is not opened when port is :const:`None` and a successive call
	to :meth:`open` will be needed.

	Possible values for the parameter port:

	- Number: number of device, numbering starts at zero.
	- Device name: depending on operating system. e.g. ``/dev/ttyUSB0``
	on GNU/Linux or ``COM3`` on Windows.

	Possible values for the parameter timeout:

	- ``timeout = None``: wait forever
	- ``timeout = 0``: non-blocking mode (return immediately on read)
	- ``timeout = x``: set timeout to ``x`` seconds (float allowed)


	.. method:: open()

	Open port.

	.. method:: close()

	Close port immediately.


	The following methods may raise :exc:`ValueError` when applied to a closed
	port.

	.. method:: read(size=1)

	:param size: Number of bytes to read.
	:return: Bytes read from the port.

	Read size bytes from the serial port. If a timeout is set it may
	return less characters as requested. With no timeout it will block
	until the requested number of bytes is read.

	.. versionchanged:: 2.5
	Returns an instance of :class:`bytes` when available (Python 2.6
	and newer) and :class:`str` otherwiese.

	.. method:: write(data)

	:param data: Data to send.
	:return: Number of bytes written.
	:exception SerialTimeoutException:
	In case a write timeout is configured for the port and the time is
	exceeded.

	Write the string data to the port.

	.. versionchanged:: 2.5
	Accepts instances of :class:`bytes` and :class:`bytearray` when
	available (Python 2.6 and newer) and :class:`str` otherwiese.

	.. method:: inWaiting()

	Return the number of chars in the receive buffer.

	.. method:: flush()

	Flush of file like objects. In this case, wait until all data is
	written.

	.. method:: flushInput()

	Flush input buffer, discarding all it's contents.

	.. method:: flushOutput()

	Clear output buffer, aborting the current output and
	discarding all that is in the buffer.

	.. method:: sendBreak(duration=0.25)

	:param duration: Time (float) to activate the BREAK condition.

	Send break condition. Timed, returns to idle state after given
	duration.

	.. method:: setBreak(level=True)

	:param level: when true activate BREAK condition, else disable.

	Set break: Controls TXD. When active, no transmitting is possible.

	.. method:: setRTS(level=True)

	:param level: Set control line to logic level.

	Set RTS line to specified logic level.

	.. method:: setDTR(level=True)

	:param level: Set control line to logic level.

	Set DTR line to specified logic level.

	.. method:: getCTS()

	:return: Current state (boolean)

	Return the state of the CTS line.

	.. method:: getDSR()

	:return: Current state (boolean)

	Return the state of the DSR line.

	.. method:: getRI()

	:return: Current state (boolean)

	Return the state of the RI line.

	.. method:: getCD()

	:return: Current state (boolean)

	Return the state of the CD line

	Read-only attributes:

	.. attribute:: name

	Device name. This is always the device name even if the
	port was opened by a number. (Read Only).

	.. versionadded:: 2.5

	.. attribute:: portstr

	:deprecated: use :attr:`name` instead

	.. attribute:: BAUDRATES

	A list of valid baud rates. The list may be incomplete such that higher
	baud rates may be supported by the device and that values in between the
	standard baud rates are supported. (Read Only).

	.. attribute:: BYTESIZES

	A list of valid byte sizes for the device (Read Only).

	.. attribute:: PARITIES

	A list of valid parities for the device (Read Only).

	.. attribute:: STOPBITS

	A list of valid stop bit widths for the device (Read Only).


	New values can be assigned to the following attributes, the port will be
	reconfigured, even if it's opened at that time:

	.. attribute:: port

	Port name/number as set by the user.

	.. attribute:: baudrate

	Current baud rate setting.

	.. attribute:: bytesize

	Byte size in bits.

	.. attribute:: parity

	Parity setting.

	.. attribute:: stopbits

	Stop bit with.

	.. attribute:: timeout

	Timeout setting (seconds, float).

	.. attribute:: xonxoff

	If Xon/Xoff flow control is enabled.

	.. attribute:: rtscts

	If hardware flow control is enabled.

	Platform specific methods.

	.. warning:: Programs using the following methods are not portable to other platforms!

	.. method:: nonblocking()

	:platform: Unix

	Configure the device for nonblocking operations. This can be useful if
	the port is used with ``select``.

	.. method:: fileno()

	:platform: Unix
	:return: File descriptor.

	Return file descriptor number for the port that is opened by this object.

	.. method:: setXON(level=True)

	:platform: Windows
	:param level: Set flow control state.

	Set software flow control state.


	.. class:: SerialBase

	The following attributes are implemented as properties. They work with open
	and closed ports.

	.. attribute:: port

	Read or write port. When the port is already open, it will be closed
	and reopened with the new setting.

	.. attribute:: baudrate

	Read or write current baud rate setting.

	.. attribute:: bytesize

	Read or write current data byte size setting.

	.. attribute:: parity

	Read or write current parity setting.

	.. attribute:: stopbits

	Read or write current stop bit width setting.

	.. attribute:: timeout

	Read or write current read timeout setting.

	.. attribute:: writeTimeout

	Read or write current write timeout setting.

	.. attribute:: xonxoff

	Read or write current software flow control rate setting.

	.. attribute:: rtscts

	Read or write current hardware flow control setting.

	.. attribute:: dsrdtr

	Read or write current hardware flow control setting.

	.. attribute:: interCharTimeout

	Read or write current inter character timeout setting.

	The following constants are also provided:

	.. attribute:: BAUDRATES

	A tuple of standard baud rate values. The actual device may support more
	or less...

	.. attribute:: BYTESIZES

	A tuple of supported byte size values.

	.. attribute:: PARITIES

	A tuple of supported parity settings.

	.. attribute:: STOPBITS

	A tuple of supported stop bit settings.

	.. method:: readline(size=None, eol='\\n')

	:param size: Max number of bytes to read, ``None`` -> no limit.
	:param eol: The end of line character.

	Read a line which is terminated with end-of-line (eol) character
	(``\\n`` by default) or until timeout.

	.. method:: readlines(sizehint=None, eol='\\n')

	:param size: Ignored parameter.
	:param eol: The end of line character.

	Read a list of lines, until timeout. sizehint is ignored and only
	present for API compatibility with built-in File objects.

	.. method:: xreadlines(sizehint=None)

	Just calls :meth:`readlines` - here for compatibility.

	For compatibility with the :mod:`io` library are the following methods.

	.. method:: readable()

	:return: True
	.. versionadded:: 2.5

	.. method:: writable()

	:return: True
	.. versionadded:: 2.5

	.. method:: seekable()

	:return: False
	.. versionadded:: 2.5

	.. method:: readinto(b)

	:param b: bytearray or array instace
	:return: Number of byte read

	Read up to len(b) bytes into bytearray b and return the number of bytes read.

	.. versionadded:: 2.5


	.. note::

	For systems that provide the :mod:`io` library (Python 2.6 and newer), the
	class :class:`Serial` will derrive from :class:`io.RawIOBase`. For all
	others from :class:`FileLike`.

	.. class:: FileLike

	An abstract file like class. It is used as base class for :class:`Serial`.

	This class implements :meth:`readline` and :meth:`readlines` based on read
	and :meth:`writelines` based on write. This class is used to provide the
	above functions for to Serial port objects.

	Note that when the serial port was opened with no timeout that
	:meth:`readline` blocks until it sees a newline (or the specified size is
	reached) and that :meth:`readlines` would never return and therefore
	refuses to work (it raises an exception in this case)!

	.. method:: writelines(sequence)

	Write a list of strings to the port.


	The following three methods are overridden in :class:`Serial`.

	.. method:: flush()

	Flush of file like objects. It's a no-op in this class, may be overridden.

	.. method:: read()

	Raises NotImplementedError, needs to be overridden by subclass.

	.. method:: write(data)

	Raises NotImplementedError, needs to be overridden by subclass.

	The following functions are implemented for compatibility with other
	file-like objects, however serial ports are not seekable.


	.. method:: seek(pos, whence=0)

	:exception IOError: always, as method is not supported on serial port

	.. versionadded:: 2.5

	.. method:: tell()

	:exception IOError: always, as method is not supported on serial port

	.. versionadded:: 2.5

	.. method:: truncate(self, n=None)

	:exception IOError: always, as method is not supported on serial port

	.. versionadded:: 2.5

	.. method:: isatty()

	:exception IOError: always, as method is not supported on serial port

	.. versionadded:: 2.5

	To be able to use the file like object as iterator for e.g.
	``for line in Serial(0): ...`` usage:

	.. method:: next()

	Return the next line by calling :meth:`readline`.

	.. method:: __iter__()

	Returns self.



	Exceptions
	==========

	.. exception:: SerialException

	Base class for serial port exceptions.

	.. versionchanged:: 2.5
	Now derrives from :exc:`IOError` instead of :exc:`Exception`

	.. exception:: SerialTimeoutException

	Exception that is raised on write timeouts.


	Constants
	=========

	Parity
	------
	.. data:: PARITY_NONE
	.. data:: PARITY_EVEN
	.. data:: PARITY_ODD
	.. data:: PARITY_MARK
	.. data:: PARITY_SPACE

	Stop bits
	---------
	.. data:: STOPBITS_ONE
	.. data:: STOPBITS_ONE_POINT_FIVE
	.. data:: STOPBITS_TWO

	Byte size
	---------
	.. data:: FIVEBITS
	.. data:: SIXBITS
	.. data:: SEVENBITS
	.. data:: EIGHTBITS

	Others
	-------
	Default control characters for software flow control:

	.. data:: XON
	.. data:: XOFF

	Module version:

	.. data:: VERSION

	A string indicating the pySerial version, such as ``2.5``.

	Functions:

	.. function:: device(number)

	:param number: Port number.
	:return: String containing device name.
	:deprecated: Use device names directly.

	Convert a port number to a platform dependent device name. Unfortunately
	this does not work well for all platforms; e.g. some may miss USB-Serial
	converters and enumerate only internal serial ports.

	The conversion may be made off-line, that is, there is no guarantee that
	the returned device name really exists on the system.