add job status methods.

CHANGELOG.md

@@ -16,6 +16,11 @@ The format is based on [Keep a Changelog].
 
 ## [UNRELEASED]
 
+### Added
+
+- `IBMQJob` now has three new methods: `done()`, `running()`, and
+  `cancelled()`. The methods are used to indicate the job status. (\#494)
+
 ### Changed
 
 - The Exception hierarchy has been refined with more specialized classes. 

qiskit/providers/ibmq/job/ibmqjob.py

@@ -290,6 +290,41 @@ def status(self) -> JobStatus:
 
         return self._status
 
+    def done(self) -> bool:
+        """Return whether the job has successfully run.
+
+        Returns:
+            True if job status is done, else false.
+        """
+        return self._is_job_status(JobStatus.DONE)
+
+    def running(self) -> bool:
+        """Return whether the job is actively running.
+
+        Returns:
+            True if job status is running, else false.
+        """
+        return self._is_job_status(JobStatus.RUNNING)
+
+    def cancelled(self) -> bool:
+        """Return whether the job has been cancelled.
+
+        Returns:
+            True if job status is cancelled, else false.
+        """
+        return self._is_job_status(JobStatus.CANCELLED)
+
+    def _is_job_status(self, job_status: JobStatus) -> bool:
+        """Return whether the current job status matches the desired one.
+
+        Args:
+            job_status: the job status to check against.
+
+        Returns:
+            True if the current job status matches the desired one, else false.
+        """
+        return self.status() == job_status
+
     def _update_status_position(
             self,
             status: ApiJobStatus,

test/ibmq/test_ibmq_job_states.py

@@ -125,6 +125,39 @@ def test_unrecognized_status(self):
         with self.assertRaises(IBMQJobApiError):
             self.wait_for_initialization(job)
 
+    def test_done_status(self):
+        """Test checking whether the job status is done while progressing job states."""
+        job = self.run_with_api(QueuedAPI())
+
+        self.assertFalse(job.done())
+        self.wait_for_initialization(job)
+
+        self._current_api.progress()
+        self.assertFalse(job.done())
+
+        self._current_api.progress()
+        self.assertTrue(job.done())
+
+    def test_running_status(self):
+        """Test checking whether the job status is running while progressing job states."""
+        job = self.run_with_api(ValidatingAPI())
+
+        self.assertFalse(job.running())
+        self.wait_for_initialization(job)
+
+        self._current_api.progress()
+        self.assertTrue(job.running())
+
+    def test_cancelled_status(self):
+        """Test checking whether the job status is cancelled while progressing job states."""
+        job = self.run_with_api(CancellableAPI())
+
+        self.assertFalse(job.cancelled())
+        self.wait_for_initialization(job)
+
+        self._current_api.progress()
+        self.assertTrue(job.cancelled())
+
     def test_validating_job(self):
         job = self.run_with_api(ValidatingAPI())