[reports][models] Fix key search in dictionaries

beat/web/reports/models.py

@@ -301,11 +301,11 @@ class Report(models.Model):
 
         report_content = json.loads(self.content)
 
-        if not report_content.has_key("alias_experiments"):
+        if "alias_experiments" not in report_content:
             report_content["alias_experiments"] = {}
 
         for experiment in self.experiments.iterator():
-            if not report_content["alias_experiments"].has_key(experiment.fullname()):
+            if experiment.fullname() not in report_content["alias_experiments"]:
                 report_content["alias_experiments"][experiment.fullname()] = experiment.name
             try:
                 index = alias_filter.index(report_content["alias_experiments"][experiment.fullname()])