diff --git a/picomon/attrtree.py b/picomon/attrtree.py
index d779c116edf56c326a7618069ee0985948250194..ea65a745b71c152af359648304490450e812c40f 100644
--- a/picomon/attrtree.py
+++ b/picomon/attrtree.py
@@ -22,7 +22,7 @@ class AttrTree(object):
         return self._attrs[key]
 
     def __setitem__(self, key, value):
-        if not key in self._attrs:
+        if key not in self._attrs:
             raise KeyError('Key "%s" does not exist' % key)
         elif isinstance(self._attrs[key], AttrTree):
             raise KeyError('Key "%s" is not settable' % key)
diff --git a/picomon_watchdog.py b/picomon_watchdog.py
index 7facb12e51d525d451fa4270814a99cfd9d2d98a..a55cdf91640708c46fb976dfdaa1762962c2b56c 100644
--- a/picomon_watchdog.py
+++ b/picomon_watchdog.py
@@ -9,21 +9,20 @@ from picomon import mails
 # launch picomon
 retcode = subprocess.call(["python3", "picomon.py"] + sys.argv[1:])
 
-# load config file
-# (unprotected, will trigger exceptions if problems but real picomon beforehand)
+# load config file (unprotected, will trigger exceptions if problems but real
+#                   picomon beforehand)
 configfile = "config.py"
 
 if "-c" in sys.argv:
-  configfile = sys.argv[sys.argv.index("-c")+1]
+    configfile = sys.argv[sys.argv.index("-c")+1]
 if "--config" in sys.argv:
-  configfile = sys.argv[sys.argv.index("--config")+1]
+    configfile = sys.argv[sys.argv.index("--config")+1]
 
 sys.path.append(os.path.dirname(configfile))
-filename  = os.path.basename(configfile)
+filename = os.path.basename(configfile)
 base, ext = os.path.splitext(filename)
 importlib.import_module(base)
 
 # send warning
 mails.send_email(config.emails.watchdog_subject,
                  "Picomon exited with status %s" % retcode)
-