Performance fix (PyCQA#502)

* Fix PyCQA#490 -- Fix performance issue introduced in 1.6.0

The lines were introduced in 7c4b9fa
and have two effects. First they cause `get_issue_list` to run twice and before
the user receives feedback that bandit started running. Secondly it does not
display any output if no issues are found, which is an unintended behavior change.

* add namespaces for parent attributes

* pylint formatting changes

* made bandit_parent a private attr

* temporary fix; perf issue only on quiet

* update perf issue

bandit/formatters/screen.py

@@ -172,8 +172,7 @@ def report(manager, fileobj, sev_level, conf_level, lines=-1):
     """
 
     bits = []
-    issues = manager.get_issue_list(sev_level, conf_level)
-    if len(issues) or not manager.quiet:
+    if not manager.quiet or manager.results_count(sev_level, conf_level):
         bits.append(header("Run started:%s", datetime.datetime.utcnow()))
 
         if manager.verbose:

bandit/formatters/text.py

@@ -141,9 +141,8 @@ def report(manager, fileobj, sev_level, conf_level, lines=-1):
     """
 
     bits = []
-    issues = manager.get_issue_list(sev_level, conf_level)
 
-    if len(issues) or not manager.quiet:
+    if not manager.quiet or manager.results_count(sev_level, conf_level):
         bits.append("Run started:%s" % datetime.datetime.utcnow())
 
         if manager.verbose: