Bugfix - check for lint object instead of pylint

ftplugin/python/pylint_fn.py

@@ -3,13 +3,16 @@ Get pylint oputput on current buffer
 """
 import sys
 import re
+try:
     from StringIO import StringIO
+except ImportError:
+    from io import StringIO
 
 try:
     from pylint import lint
     from pylint.reporters.text import TextReporter
 except ImportError:
-    raise AssertionError('Error: pylint_fm.vim requires module pylint')
+    lint = None
 
 import vim
 
@@ -25,6 +28,10 @@ class VImPylint(object):
     def run(self):
         """execute pylint and fill the quickfix"""
 
+        if not lint:
+            vim.command("echo 'Error: pylint_fm.vim requires module pylint'")
+            return
+
         # clear QF window
         vim.command('call setqflist([])')
 

ftplugin/python/pylint_fn.vim

@@ -46,10 +46,8 @@
 
 let s:plugin_path = expand('<sfile>:p:h', 1)
 
-if exists("b:did_pylint_plugin")
+if exists(":Pylint")
     finish " only load once
-else
-    let b:did_pylint_plugin = 1
 endif
 
 function! s:SetPython(msg)