Skip line if NULL(Puthon)

Can yoy pls help me. I have code

    run_list = []
count = 0
try:
        for run in json['value']:
                count+=1
                Run_ID = run['id']
                Name = run['name']
                IsAutomated = run['isAutomated']
                State = run['state']
                Total_Tests = run['totalTests']
                IncompleteTests = run['incompleteTests']
                NotApplicableTests = run['notApplicableTests']
                PassedTests = run['passedTests']
                UnanalyzedTests = run['unanalyzedTests']
                Revision = run['revision']
                webAccessUrl = run['webAccessUrl']
                StartedDate = run['startedDate']
                CompletedDatef = json.get('completedDate','1999-01-01T00:00:00.523Z')
                CompletedDate = run['completedDate']
                ProjectSK = run['project']['id']
                Url = run['url']
                State = run['state']
                #result = {'Run_ID':Run_ID, 'Run_Name': Name, 'IsAutomated' : IsAutomated, 'Total_Tests' : Total_Tests, 'IncompleteTests' : IncompleteTests, 'NotApplicableTests' : NotApplicableTests, 'PassedTests' : PassedTests, 'UnanalyzedTests' : UnanalyzedTests,'Revision' : Revision ,'webAccessUrl' : webAccessUrl, 'StartedDate' : StartedDate, 'CompletedDate' : CompletedDate, 'ProjectSK' : ProjectSK, 'Url' : Url, 'State' : State}
                result = {'Run_ID':Run_ID,'Run_Name':Name,'IsAutomated':IsAutomated,'Total_Tests':Total_Tests,'IncompleteTests':IncompleteTests,'NotApplicableTests':NotApplicableTests,'PassedTests':PassedTests,'UnanalyzedTests':UnanalyzedTests,'Revision':Revision,'webAccessUrl':webAccessUrl,'StartedDate':StartedDate,'CompletedDate':CompletedDate,'ProjectSK':ProjectSK,'Url':Url,'State':State}
                run_list.append(result)
                #print(run_list)
                #print(str(count) + "     " + str(Run_ID) + "   CompletedDate "+ str(CompletedDate)+ "  CompletedDatef   " +str(CompletedDatef))
except:
                 #type(CompletedDate)
                 pass
                 print(str(count) + "     " + str(Run_ID) + "   CompletedDate "+ str(CompletedDate)+ "  CompletedDatef   " +str(CompletedDatef))

After exec him i see that CompletedDate is null and cycle break. Can you tell me pls how can i skip line with NULL?