Allow SecondaryStatusTransitions to be missing in secondary_training_status_message (#331)

Author: icywang86rui

src/sagemaker/utils.py

@@ -173,7 +173,10 @@ def secondary_training_status_message(job_description, prev_description):
             or len(job_description.get('SecondaryStatusTransitions')) == 0:
         return ''
 
-    prev_transitions_num = len(prev_description['SecondaryStatusTransitions']) if prev_description is not None else 0
+    prev_description_secondary_transitions = prev_description.get('SecondaryStatusTransitions')\
+        if prev_description is not None else None
+    prev_transitions_num = len(prev_description['SecondaryStatusTransitions'])\
+        if prev_description_secondary_transitions is not None else 0
     current_transitions = job_description['SecondaryStatusTransitions']
 
     if len(current_transitions) == prev_transitions_num:

tests/unit/test_utils.py

@@ -155,3 +155,14 @@ def test_secondary_training_status_message_status_not_changed():
     now = datetime.now()
     TRAINING_JOB_DESCRIPTION_1['SecondaryStatusTransitions'][-1]['StartTime'] = now
     assert secondary_training_status_message(TRAINING_JOB_DESCRIPTION_1, TRAINING_JOB_DESCRIPTION_2) == MESSAGE
+
+
+def test_secondary_training_status_message_prev_missing():
+    now = datetime.now()
+    TRAINING_JOB_DESCRIPTION_1['SecondaryStatusTransitions'][-1]['StartTime'] = now
+    expected = '{} {} - {}'.format(
+        datetime.utcfromtimestamp(time.mktime(now.timetuple())).strftime('%Y-%m-%d %H:%M:%S'),
+        STATUS,
+        MESSAGE
+    )
+    assert secondary_training_status_message(TRAINING_JOB_DESCRIPTION_1, {}) == expected