Post-review fixes 1 - use ast instead of _ast, comment

bandit/core/utils.py

@@ -6,7 +6,7 @@
 import logging
 import os.path
 import sys
-from _ast import Constant
+from ast import Constant
 
 try:
     import configparser
@@ -378,6 +378,8 @@ def get_nosec(nosec_lines, context):
         # use the last line in the case of multi-line strings:
         # """some text
         # with many lines"""  # nosec ...
+        # Strings are parsed as ast.Constant since Python 3.8,
+        # for Python 3.7 context['lineno'] is returned for strings.
         lineno = context['linerange'][-1]
     else:
         lineno = context['lineno']