Source code for envipyengine.task

The ENVI Py Engine task object provides task information and can submit a job to the Task Engine with input.
from __future__ import absolute_import
from abc import abstractmethod, abstractproperty
from string import Template
from pprint import PrettyPrinter
from .envipymeta import ENVIPyMeta
from .utils import with_metaclass

[docs]class Task(with_metaclass(ENVIPyMeta, object)): """ The ENVI Py Engine Task object represents a Task Engine task and its parameters. :Example: Import the modules for the example. >>> from envipyengine import Engine >>> from pprint import pprint Create an Engine object for ENVI and get a task >>> envi_engine = Engine('ENVI') >>> task = envi_engine.task('SpectralIndex') Investigate task information. >>> print( 'SpectralIndex' >>> print(task.description, type(task.description)) ('This task creates a spectral index raster from one pre-defined spectral index. Spectral indices are combinations of surface reflectance at two or more wavelengths that indicate relative abundance of features of interest.', <type 'str'>) >>> print(task.display_name, type(task.display_name)) ('Spectral Index', <type 'str'>) >>> task_parameters = task.parameters >>> pprint(task_parameters) Execute a job using the Task Engine >>> input_raster = dict(url='C:\\Program Files\\Harris\\ENVI54\\data\\qb_boulder_msi', factory='URLRaster') >>> parameters = dict(INPUT_RASTER=input_raster, INDEX='Normalized Difference Vegetation Index') >>> result = task.execute(parameters) """ def __str__(self): pretty_print = PrettyPrinter(indent=2) props = dict(, display_name=self.display_name, description=self.description, parameters=pretty_print.pformat(self.parameters)) return Template(''' name: ${name} display_name: ${display_name} description: ${description} parameters: ${parameters} ''').substitute(props) def __repr__(self): return self.__str__() def __unicode__(self): return self.__str__() @abstractmethod def __init__(self, uri=None, cwd=None): """ Returns an ENVI Py Engine Task object based on the task name. :param uri: A String representing the unique id of the task. :param cwd: A String representing the current working directory for the engine execution. :return: None """ self._uri = uri self._cwd = cwd @abstractproperty def name(self): """ The name of the task :return: a string """ pass @abstractproperty def display_name(self): """ The display name of the task :return: a string """ pass @abstractproperty def description(self): """ The task description :return: a string """ pass @abstractproperty def uri(self): """ The task unique identifier """ pass @abstractproperty def parameters(self): """ A list of the task parameter definitions. Each task parameter is a dictionary containing, but not limited to, the following keys: ================= ========== ================= ========================================================== Key Data Type Type Description ================= ========== ================= ========================================================== name string Required The name of the parameter display_name string Required The display name of the parameter type string Required The parameter data type direction string Required Can be *input* or *output* description string Required The parameter description required bool Required Indicates if the parameter is required on input when submitting a job dimensions string Optional Indicates if the parameter is an array if set. Dimesions is of the format *[dim1,dim2,...]* choice_list list Optional A list of available choices for the parameter input min type Optional The minimum value allowed for the parameter max type Optional The maximum value allowed for the parameter ================= ========== ================= ========================================================== :return: a list of parameter dictionaries """ pass @abstractmethod
[docs] def execute(self, parameters, cwd=None): """ Executes a synchronous task using the Task Engine :param parameters: A dictionary of key-value pairs of parameter names and values. The dictionary serves as input to the job. :param cwd: Set to the current working directory the engine will run in. Defaults to the python current working directory if none specified. :return: A dictionary containing the Task Engine output. """ pass