inspektor: Use pylint help text to find appropriate flags

Let's use a heuristic that tends to be more reliable instead
of looking for python versions or pylint version strings:
Check directly the --help output. Since in most py apps
the output is auto generated from real command line options,
this should be relatively safe.

This solves a problem with moving target options such as
--score and others.

Signed-off-by: Lucas Meneghel Rodrigues <lookkas@gmail.com>

inspektor/lint.py

@@ -19,6 +19,7 @@
 from pylint.lint import Run
 
 from .path import PathChecker
+from .utils import process
 
 
 class Linter(object):
@@ -45,10 +46,15 @@ def __init__(self, args, logger=logging.getLogger('')):
             self.log.info('Pylint enabled : %s' % self.enabled_errors)
         else:
             self.log.info('Verbose mode, no disable/enable, full reports')
+        help_result = process.run('pylint --help')
+        self.help_text = help_result.stdout
 
     def set_verbose(self):
         self.verbose = True
 
+    def _pylint_has_option(self, option):
+        return option in self.help_text
+
     def get_opts(self):
         """
         If VERBOSE is set, show pylint reports. If not, only an issue summary.
@@ -63,8 +69,9 @@ def get_opts(self):
                 pylint_args.append('--disable=%s' % self.ignored_errors)
             if self.enabled_errors:
                 pylint_args.append('--enable=%s' % self.enabled_errors)
-            pylint_args.append('--reports=no')
-            if sys.version_info[:2] > (2, 6):
+            if self._pylint_has_option('--reports'):
+                pylint_args.append('--reports=no')
+            if self._pylint_has_option('--score'):
                 pylint_args.append('--score=no')
 
         return pylint_args

inspektor/utils/process.py

@@ -67,8 +67,8 @@ def run(cmd, verbose=True, ignore_status=False, shell=False):
     duration = time.time() - start
     result = CmdResult(cmd)
     result.exit_status = p.returncode
-    result.stdout = stdout
-    result.stderr = stderr
+    result.stdout = str(stdout)
+    result.stderr = str(stderr)
     result.duration = duration
     if p.returncode != 0 and not ignore_status:
         raise exceptions.CmdError(cmd, result)