Python doctest file to simulate a WPS Execute invocation.
This test does not execute any live HTTP request, rather it parses XML files containing pre-made HTTP responses.

Imports

    >>> from __future__ import (absolute_import, division, print_function)
    >>> from tests.utils import resource_file, setup_logging
    >>> from owslib.wps import WebProcessingService
    >>> logger = setup_logging('INFO')

Initialize WPS client

    >>> wps = WebProcessingService('http://cida.usgs.gov/gdp/process/WebProcessingService')

Execute fake invocation of Execute operation using cached HTTP request and response

    >>> request = open(resource_file('wps_USGSExecuteRequest1.xml'), 'rb').read()
    >>> response = open(resource_file('wps_USGSExecuteResponse1a.xml'), 'rb').read()
    >>> execution = wps.execute(None, [], request=request, response=response)
    Executing WPS request...
    Execution status=ProcessStarted
    Percent completed=0
    Status message=None
    >>> execution.status
    'ProcessStarted'
    >>> execution.isComplete()
    False

Simulate end of process

    >>> response = open(resource_file('wps_USGSExecuteResponse1b.xml'), 'rb').read()
    >>> execution.checkStatus(sleepSecs=0, response=response)
    Execution status=ProcessSucceeded
    Percent completed=0
    Status message=Process successful
    >>> execution.status
    'ProcessSucceeded'
    >>> execution.isComplete()
    True

Display location of process output
    >>> for output in execution.processOutputs:
    ...     output.reference
    ... 
    'http://cida.usgs.gov/climate/gdp/process/RetrieveResultServlet?id=1318528582026OUTPUT.601bb3d0-547f-4eab-8642-7c7d2834459e'
