Add a LintianSeverity for lintian-clean packages. + PEP8 compliance

debexpo/plugins/qa/lintian.py

@@ -67,12 +67,16 @@ severities = {
                          constants.PLUGIN_SEVERITY_INFO),
     'X': LintianSeverity('Package has lintian experimental tags', 0,
                          constants.PLUGIN_SEVERITY_INFO),
+    '': LintianSeverity('Package is lintian clean', -1,
+                        constants.PLUGIN_SEVERITY_INFO),
     }
 
+
 @test_result
 class LintianTest(PluginResult):
     """ Summary of the lintian results """
 
+    # -1 -> package is clean
     max_lintian_severity = string_field('max_lintian_severity')
     severity = int_field('severity')
 
@@ -159,9 +163,14 @@ class LintianPlugin(QAPlugin):
                                     + " ".join(override_comments) + ")")
                 override_comments = []
             for line in lintian_data:
-                self.new_result(LintianWarning, package=package, severity=severity,
-                                tag=lintian_tag, data=line)
+                self.new_result(LintianWarning, package=package,
+                                severity=severity, tag=lintian_tag,
+                                data=line)
+
+        if not lintian_severities:
+            max_lintian_severity = ''
 
+        else:
             max_lintian_severity = max(lintian_severities,
                                        key=lambda s: severities[s].int)
         severity = severities[max_lintian_severity].plugin_severity