include::genpy::message Namespace Reference

Classes
class	DeserializationError
class	Message
class	MessageException
class	SerializationError
Functions
def	_convert_getattr
def	_fill_message_args
def	_fill_val
def	_get_message_or_service_class
def	check_type
def	fill_message_args
def	get_message_class
def	get_printable_message_args
def	get_service_class
def	isstring
def	strify_message
Variables
dictionary	_message_class_cache = {}
	cache for get_message_class
dictionary	_service_class_cache = {}
	cache for get_service_class
dictionary	_widths
	long = int
tuple	struct_I = struct.Struct('<I')

---

Function Documentation

def include.genpy.message._convert_getattr	(		val,
			f,
			t
	)		[private]

Convert atttribute types on the fly, if necessary.  This is mainly
to convert uint8[] fields back to an array type.

Definition at line 163 of file message.py.

def include.genpy.message._fill_message_args	(		msg,
			msg_args,
			keys,
			prefix = ''
	)		[private]

Populate message with specified args.

:param msg: message to fill, ``Message``
:param msg_args: list of arguments to set fields to, ``[args]``
:param keys: keys to use as substitute values for messages and timestamps.  ``dict``
:param prefix: field name prefix (for verbose printing), ``str``
:returns: unused/leftover message arguments.  ``[args]``
:raise :exc:`MessageException` If not enough message arguments to fill message
:raises: :exc:`ValueError` If msg or msg_args is not of correct type

Definition at line 467 of file message.py.

def include.genpy.message._fill_val	(		msg,
			f,
			v,
			keys,
			prefix
	)		[private]

Subroutine of L{_fill_message_args()}. Sets a particular field on a message
:param f: field name, ``str``
:param v: field value
:param keys: keys to use as substitute values for messages and timestamps, ``dict``
:raises: exc:`MessageException`

Definition at line 396 of file message.py.

def include.genpy.message._get_message_or_service_class	(		type_str,
			message_type,
			reload_on_error = False
	)		[private]

Utility for retrieving message/service class instances. Used by
get_message_class and get_service_class.
:param type_str: 'msg' or 'srv', ``str``
:param message_type: type name of message/service, ``str``
:returns: Message/Service  for message/service type or None, ``class``
:raises: :exc:`ValueError` If message_type is invalidly specified

Definition at line 547 of file message.py.

def include.genpy.message.check_type	(		field_name,
			field_type,
			field_val
	)

Dynamic type checker that maps ROS .msg types to python types and
verifies the python value.  check_type() is not designed to be
fast and is targeted at error diagnosis. This type checker is not
designed to run fast and is meant only for error diagnosis.

:param field_name: ROS .msg field name, ``str``
:param field_type: ROS .msg field type, ``str``
:param field_val: field value, ``Any``
:raises: :exc:`SerializationError` If typecheck fails

Definition at line 187 of file message.py.

def include.genpy.message.fill_message_args	(		msg,
			msg_args,
			keys = {}
	)

Populate message with specified args. Args are assumed to be a
list of arguments from a command-line YAML parser. See
http://www.ros.org/wiki/ROS/YAMLCommandLine for specification on
how messages are filled.

fill_message_args also takes in an optional 'keys' dictionary
which contain substitute values for message and time types. These
values must be of the correct instance type, i.e. a Message, Time,
or Duration. In a string key is encountered with these types, the
value from the keys dictionary will be used instead. This is
mainly used to provide values for the 'now' timestamp.

:param msg: message to fill, ``Message``
:param msg_args: list of arguments to set fields to, or
  If None, msg_args will be made an empty list., ``[args]``
:param keys: keys to use as substitute values for messages and timestamps, ``dict``
:raises: :exc:`MessageException` If not enough/too many message arguments to fill message

Definition at line 507 of file message.py.

def include.genpy.message.get_message_class	(		message_type,
			reload_on_error = False
	)

Get the message class. NOTE: this function maintains a
local cache of results to improve performance.
:param message_type: type name of message, ``str``
:param reload_on_error: (optional). Attempt to reload the Python
  module if unable to load message the first time. Defaults to
  False. This is necessary if messages are built after the first load.
:returns: Message class for message/service type, ``Message class``
:raises :exc:`ValueError`: if  message_type is invalidly specified

Definition at line 606 of file message.py.

def include.genpy.message.get_printable_message_args	(		msg,
			buff = None,
			prefix = ''
	)

Get string representation of msg arguments
:param msg: msg message to fill, ``Message``
:param prefix: field name prefix (for verbose printing), ``str``
:returns: printable representation of  msg args, ``str``

Definition at line 370 of file message.py.

def include.genpy.message.get_service_class	(		service_type,
			reload_on_error = False
	)

Get the service class. NOTE: this function maintains a
local cache of results to improve performance.
:param service_type: type name of service, ``str``
:param reload_on_error: (optional). Attempt to reload the Python
  module if unable to load message the first time. Defaults to
  False. This is necessary if messages are built after the first load.
:returns: Service class for service type, ``Service class``
:raises :exc:`Exception` If service_type is invalidly specified

Definition at line 627 of file message.py.

def include.genpy.message.isstring

(

s

)

Small helper version to check an object is a string in a way that works
for both Python 2 and 3

Definition at line 59 of file message.py.

def include.genpy.message.strify_message	(		val,
			indent = '',
			time_offset = None,
			current_time = None,
			field_filter = None,
			fixed_numeric_width = None
	)

Convert value to string representation
:param val: to convert to string representation. Most likely a Message.  ``Value``
:param indent: indentation. If indent is set, then the return value will have a leading \n, ``str``
:param time_offset: if not None, time fields will be displayed
  as deltas from  time_offset, ``Time``

:param current_time: currently not used. Only provided for API
  compatibility. current_time passes in the current time with
  respect to the message, ``Time``
:param field_filter: filter the fields that are strified for Messages, ``fn(Message)->iter(str)``
:returns: string (YAML) representation of message, ``str``

Definition at line 84 of file message.py.

---

Variable Documentation

dictionary include::genpy::message::_message_class_cache = {}

cache for get_message_class

Definition at line 604 of file message.py.

dictionary include::genpy::message::_service_class_cache = {}

cache for get_service_class

Definition at line 625 of file message.py.

dictionary include::genpy::message::_widths

Initial value:

{
    'byte': 8, 'char': 8, 'int8': 8, 'uint8': 8,
    'int16': 16, 'uint16': 16,
    'int32': 32, 'uint32': 32,
    'int64': 64, 'uint64': 64,
}

Definition at line 180 of file message.py.

include::genpy::message::long = int

Definition at line 55 of file message.py.

tuple include::genpy::message::struct_I = struct.Struct('<I')

Definition at line 57 of file message.py.