def example_create_sequence(base):
print("Creating Action for Sequence")
angular_action = create_angular_action()
cartesian_action = create_cartesian_action()
print("Creating Sequence")
sequence = Base_pb2.Sequence()
sequence.name = "Example sequence"
print("Appending Actions to Sequence")
task_1 = sequence.tasks.add()
task_1.group_identifier = 0
task_1.action.CopyFrom(angular_action)
task_2 = sequence.tasks.add()
task_2.group_identifier = 1 # sequence elements with same group_id are played at the same time
task_2.action.CopyFrom(cartesian_action)
print("Creating sequence on device and executing it")
handle_sequence = base.CreateSequence(sequence)
base.PlaySequence(handle_sequence)
print("Waiting 30 seconds for movement to finish ...")
time.sleep(30)
print("Sequence completed")
def example_create_sequence(base, base_cyclic):
print("Creating Action for Sequence")
actuator_count = base.GetActuatorCount().count
angular_action = create_angular_action(actuator_count)
cartesian_action = create_cartesian_action(base_cyclic)
print("Creating Sequence")
sequence = Base_pb2.Sequence()
sequence.name = "Example sequence"
print("Appending Actions to Sequence")
task_1 = sequence.tasks.add()
task_1.group_identifier = 0
task_1.action.CopyFrom(cartesian_action)
task_2 = sequence.tasks.add()
task_2.group_identifier = 1 # sequence elements with same group_id are played at the same time
task_2.action.CopyFrom(angular_action)
e = threading.Event()
notification_handle = base.OnNotificationSequenceInfoTopic(
check_for_sequence_end_or_abort(e), Base_pb2.NotificationOptions())
print("Creating sequence on device and executing it")
handle_sequence = base.CreateSequence(sequence)
base.PlaySequence(handle_sequence)
print("Waiting for movement to finish ...")
finished = e.wait(TIMEOUT_DURATION)
base.Unsubscribe(notification_handle)
if not finished:
print("Timeout on action notification wait")
return finished
def example_manipulation_protobuf_list():
# In Google Protocol Buffer, 'repeated' is used to designate a list of indeterminate length. Once affected to a Python
# variable they can be used in the same way as a standard list.
# Note that a repeated message field doesn't have an append() function, it has an
# add() function that create the new message object.
# For this example we will use the following two messages
# message Sequence {
# SequenceHandle handle = 1
# string name = 2
# string application_data = 3
# repeated SequenceTask tasks = 4
# }
# message SequenceTask {
# uint32 group_identifier = 1;
# Action action = 2;
# string application_data = 3;
# }
# For a clearer example the attribute action in SequenceTask message will be kept to default value
# Here's two ways to add to a repeated message field
# Create the parent message
sequence = Base_pb2.Sequence()
sequence.name = "Sequence"
# The 'extend' way
sequence_task_1 = Base_pb2.SequenceTask()
sequence_task_1.group_identifier = 10
action = sequence_task_1.action
action = Base_pb2.Action() # Using Action default constructor
sequence.tasks.extend([sequence_task_1]) # Extend expect an iterable
# Created for the add() function unique to repeated message field
sequence_task_2 = sequence.tasks.add()
sequence_task_2.group_identifier = 20
action = sequence_task_2.action
action = Base_pb2.Action() # Using Action default constructor
# Since sequence.task is a list we can use all the Python features to
# loop, iterate, interogate and print elements in that list.
for i in range(len(sequence.tasks)):
print("Sequence ID with index : {0}".format(
sequence.tasks[i].group_identifier))
# Lists have the iterator property of a Python list, so you can directly iterate
# throught element without creating a iterator as in the previous example
for task in sequence.tasks:
print("Sequence ID with object iterator : {0}".format(
task.group_identifier))
def example_manipulation_protobuf_helpers():
# Google offers some helpers with Google Protocol Buffer,
# some of which are covered in this section.
# All the module google.protobuf documentation is available here:
# https://developers.google.com/protocol-buffers/docs/reference/python/
# First, the function include with message instance. We will cover the next function
# Clear
# MergeFrom
# CopyFrom
# The Clear function is straightforward - it clears all the message attributes.
# MergeFrom and CopyFrom have the same purpose: to duplicate data into another object.
# The difference between them is that CopyFrom will do a Clear before a MergeFrom.
# For its part MergeFrom will merge data if the new field is not empty.
# In the case of repeated, the content received in a parameter will be appended.
# For this example, we'll used the SSID message
# message Ssid {
# string identifier = 1;
# }
# First we'll create four of them, each with a unique string
ssid_1 = Base_pb2.Ssid()
ssid_1.identifier = ""
ssid_2 = Base_pb2.Ssid()
ssid_2.identifier = "123"
ssid_3 = Base_pb2.Ssid()
ssid_3.identifier = "@#$"
# Now merge ssid_1 into ssid_2 and print the identifier of ssid_2
ssid_2.MergeFrom(ssid_1)
print("Content ssid_2: {0}".format(ssid_2.identifier))
# output : Content ssid_2: 123
# Now copy ssid_1 into ssid_3 and print the identifier of ssid_3
ssid_3.CopyFrom(ssid_1)
print("Content ssid_3: {0}".format(ssid_3.identifier))
# output : Content ssid_3:
# For more functions consult the Class Message documentation
# https://developers.google.com/protocol-buffers/docs/reference/python/google.protobuf.message.Message-class
# From the Google Protocol Buffer library you can use the json_format module.
# One useful function is the MessageToJson.
# This function serializes the Google Protocol Buffer message to a JSON object. It is helpful when you want to print a large object into
# a human-readable format.
# Here's an example with the following two messages
#
# message Sequence {
# SequenceHandle handle = 1
# string name = 2
# string application_data = 3
# repeated SequenceTask tasks = 4
# }
# message SequenceTask {
# uint32 group_identifier = 1;
# Action action = 2;
# string application_data = 3;
# }
# populate the message
sequence = Base_pb2.Sequence()
sequence.name = "A Name"
for i in range(5):
sequence_task = sequence.tasks.add()
sequence_task.group_identifier = 10 * (
i + 1) # Some further function doesn't print if value = 0
action = sequence_task.action
action = Base_pb2.Action() # Using Action default constructor
# need to import the module
from google.protobuf import json_format
# now get the JSON object
json_object = json_format.MessageToJson(sequence)
# now print it
print("Json object:")
print(json_object)
# output:
# Json object
# {
# "name": "A Name",
# "tasks": [
# {
# "groupIdentifier": 10
# },
# {
# "groupIdentifier": 20
# },
# {
# "groupIdentifier": 30
# },
# {
# "groupIdentifier": 40
# },
# {
# "groupIdentifier": 50
# }
# ]
# }
# From the Google Protocol Buffer library you can used the text_format module.
# A useful function is the MessageToString. It has the same purpose as
# MessageToJson - convert the message to a human readable format.
# For the example we'll reuse the sequence object created in the previous example
# First import the module
from google.protobuf import text_format
# Now print
print("Text format:")
print(text_format.MessageToString(sequence))
