misty2py 5.0.0

A Python package for Misty II development

Misty2py

Misty2py is a Python 3 package for Misty II development using Misty's REST API.

Read the full documentation here!

Installation

Poetry

To install misty2py, run pip install misty2py.

From source

• If this is your first time using misty2py from source, do following:

  • Get Poetry (python -m pip install poetry) if you do not have it yet.
  • Copy .env.example to .env.
  • Replace the placeholder values in the new .env file.
  • Run poetry install to obtain all dependencies.

• Run the desired script via poetry run python -m [name] where [name] is the placeholder for the module location (in Python notation).

• If the scripts run but your Misty does not seem to respond, you have most likely provided an incorrect IP address for MISTY_IP_ADDRESS in .env.

• Pytests can be run via poetry run pytest ..

• The coverage report can be obtained via poetry run pytest --cov-report html --cov=misty2py tests for HTML output or via poetry run pytest --cov=misty2py tests for terminal output.

Features

Misty2py can be used to develop complex skills (behaviours) for the Misty II robot utilising:

• actions via sending a POST or DELETE requests to Misty's API;
• informations via sending a GET request to Misty's API;
• continuous streams of data via subscribing to event types on Misty's websockets.

Misty2py uses following concepts for easy of usage:

• action keywords - customisable python-styled keywords for endpoints of Misty's API that correspond to performing actions;
• information keywords - customisable python-styled keywords for endpoints of Misty's API that correspond to retrieving information;
• data shortcuts - customisable python-styled keywords for commonly used data that are supplied to Misty's API as the body of a POST request.

Usage

Getting started

The main object of this package is Misty, which is an abstract representation of Misty the robot. To initialise this object, it is required to know the IP address of the Misty robot that should be used.

The most direct way to initialise a Misty object is to use the IP address directly, which allows the user to get the object in one step via:

from misty2py.robot import Misty

my_misty = Misty("192.168.0.1")  #example IP address

This may be impractical and potentially even unsafe, so it is recommended to create a .env file in the project's directory, specify the IP address there via MISTY_IP_ADDRESS="[ip_address_here]" and use Misty2py's EnvLoader to load the IP address via:

from misty2py.robot import Misty
from misty2py.utils.env_loader import EnvLoader

env_loader = EnvLoader()
my_misty = Misty(env_loader.get_ip())

Assuming a Misty object called my_misty was obtained, all required actions can be performed via the following three methods:

# Performing an action (a POST or DELETE request):
my_misty.perform_action("<action_keyword>")

# Obtaining information (a GET request):
my_misty.get_info("<information_keyword>")

# Event related methods 
# (subscribing to an event, getting event data
# or event log and unsubscribing from an event):
my_misty.event("<parameter>")

Responses

Any action performed via Misty2py which contains communication with Misty's APIs returns the Misty2pyResponse object. Misty2pyResponse is a uniform representation of two sub-responses that are present in any HTTP or WebSocket communication with Misty's APIs using Misty2py. The first sub-response is always from Misty2py and is represented by the attributes Misty2pyResponse.misty2py_status (True if no Misty2py-related errors were encountered) and potentially empty Misty2pyResponse.error_msg and Misty2pyResponse.error_type that contain error information if a Misty2py-related error was encountered. The other sub-response is either from Misty's REST API or Misty's WebSocket API. In the first case, it is represented by the attribute Misty2pyResponse.rest_response (Dict), and in the second case, it is represented by the attribute Misty2pyResponse.ws_response. One of these is always empty, because no action in Misty2py includes simultaneous communication with both APIs. For convenience, a Misty2pyResponse object can be easily parsed to a dictionary via the method Misty2pyResponse.parse_to_dict.

Obtaining information

Obtaining digital information is handled by misty2py.robot::get_info method which has two arguments. The argument info_name is required and it specifies the string information keyword corresponding to an endpoint in Misty's REST API. The argument params is optional and it supplies a dictionary of parameter name and parameter value pairs. This argument defaults to {} (an empty dictionary).

Performing actions

Performing physical and digital actions including removal of non-system files is handled by misty2py.robot::perform_action() method which takes two arguments. The argument action_name is required and it specifies the string action keyword corresponding to an endpoint in Misty’s REST API. The second argument, data, is optional and it specifies the data to pass to the request as a dictionary or a data shortcut (string). The data argument defaults to {} (an empty dictionary).

Event types

Misty's WebSocket API follows PUB-SUB architecture, which means that in order to obtain event data in Misty's framework, it is required to subscribe to an event type on Misty's WebSocket API. The WebSocket server then streams data to the WebSocket client, which receives it a separate thread. To access the data, misty2py.robot::event method must be called with "get_data" parameter from the main thread. When the data are no longer required to be streamed to the client, an event type can be unsubscribed which both kills the event thread and stops the API from sending more data.

Subscribing to an event is done via misty2py.robot::event with the parameter "subscribe" and following keyword arguments:

• type - required; event type string as documented in Event Types Docs.
• name - optional; a custom event name string; must be unique.
• return_property - optional; the property to return from Misty's websockets; all properties are returned if return_property is not supplied.
• debounce - optional; the interval in ms at which new information is sent; defaults to 250.
• len_data_entries - optional; the maximum number of data entries to keep (discards in fifo style); defaults to 10.
• event_emitter - optional; an event emitter function which emits an event upon message recieval. Supplies the message content as an argument.

Accessing the data of an event or its log is done via misty2py.robot::event with the parameter "get_data" or "get_log" and a keyword argument name (the name of the event).

Unsubscribing from an event is done via misty2py.robot::event with the parameter "unsubscribe" and a keyword argument name (the name of the event).

A bare-bones implementation of event subscription can be seen below.

import time

from misty2py.robot import Misty
from misty2py.utils.env_loader import EnvLoader

env_loader = EnvLoader

m = Misty(env_loader.get_ip())

d = m.event("subscribe", type = "BatteryCharge")
e_name = d.get("event_name")

time.sleep(1)

d = m.event("get_data", name = e_name)

d = m.event("unsubscribe", name = e_name)

The following example shows a more realistic scenario which includes an event emitter and an event listener.

import time
from pymitter import EventEmitter

from misty2py.robot import Misty
from misty2py.utils.env_loader import EnvLoader

env_loader = EnvLoader

m = Misty(env_loader.get_ip())
ee = EventEmitter()
event_name = "myevent_001"

@ee.on(event_name)
def listener(data):
    print(data)

d = m.event("subscribe", type = "BatteryCharge", 
            name = event_name, event_emitter = ee)

time.sleep(2)

d = m.event("unsubscribe", name = event_name)

Adding custom keywords and shortcuts

Custom keywords and shortcuts can be passed to a Misty object while declaring a new instance by using the optional arguments custom_info, custom_actions and custom_data.

The argument custom_info can be used to pass custom information keywords as a dictionary with keys being the information keywords and values being the endpoints. An information keyword can only be used for a GET method supporting endpoint.

The argument custom_actions can be used to pass custom action keywords as a dictionary with keys being the action keywords and values being a dictionary of an "endpoint" key (str) and a "method" key (str). The "method" values must be one of post, delete, put, head, options and patch. However, it should be noted that Misty's REST API currently only has GET, POST and DELETE methods. The rest of the methods was implement in Misty2py for forwards-compatibility.

The argument custom_data can be used to pass custom data shortcuts as a dictionary with keys being the data shortcuts and values being the dictionary of data values.

For futher illustration, an example of passing custom keywords and shortcuts can be seen below.

custom_allowed_infos = {
    "hazards_settings": "api/hazards/settings"
}

custom_allowed_data = {
    "amazement": {
        "FileName": "s_Amazement.wav"
    },
    "red": {
        "red": "255",
        "green": "0",
        "blue": "0"
    }
}

custom_allowed_actions = {
    "audio_play" : {
        "endpoint" : "api/audio/play",
        "method" : "post"
    },
    "delete_audio" : {
        "endpoint" : "api/audio",
        "method" : "delete"
    }
}

misty_robot = Misty("0.0.0.0", 
    custom_info=custom_allowed_infos, 
    custom_actions=custom_allowed_actions, 
    custom_data=custom_allowed_data)