Suggested small refactors in assignments (#1150)

This change makes use of augmented assignment statements as suggested
by issue #760.

Fixes: #760`

Signed-off-by: Eric Brown <eric_wade_brown@yahoo.com>

bandit/core/context.py

@@ -193,7 +193,7 @@ def _get_literal_value(self, literal):
         elif isinstance(literal, ast.Tuple):
             return_tuple = tuple()
             for ti in literal.elts:
-                return_tuple = return_tuple + (self._get_literal_value(ti),)
+                return_tuple += (self._get_literal_value(ti),)
             literal_value = return_tuple
 
         elif isinstance(literal, ast.Set):

bandit/formatters/xml.py

@@ -65,7 +65,7 @@ def report(manager, fileobj, sev_level, conf_level, lines=-1):
             "Test ID: %s Severity: %s Confidence: %s\nCWE: %s\n%s\n"
             "Location %s:%s"
         )
-        text = text % (
+        text %= (
             issue.test_id,
             issue.severity,
             issue.confidence,

bandit/plugins/injection_wildcard.py

@@ -124,7 +124,7 @@ def linux_commands_wildcard_injection(context, config):
             argument_string = ""
             if isinstance(call_argument, list):
                 for li in call_argument:
-                    argument_string = argument_string + f" {li}"
+                    argument_string += f" {li}"
             elif isinstance(call_argument, str):
                 argument_string = call_argument