diff --git a/moulinette/actionsmap.py b/moulinette/actionsmap.py
index 2d1d852d..4921fb9c 100644
--- a/moulinette/actionsmap.py
+++ b/moulinette/actionsmap.py
@@ -103,6 +103,7 @@ class CommentParameter(_ExtraParameter):
                             % value)
         return value
 
+
 class AskParameter(_ExtraParameter):
     """
     Ask for the argument value if possible and needed.
@@ -229,12 +230,13 @@ class RequiredParameter(_ExtraParameter):
                             % value)
         return value
 
+
 """
 The list of available extra parameters classes. It will keep to this list
 order on argument parsing.
 
 """
-extraparameters_list = [CommentParameter, AskParameter, PasswordParameter, 
+extraparameters_list = [CommentParameter, AskParameter, PasswordParameter,
                         RequiredParameter, PatternParameter]
 
 # Extra parameters argument Parser
diff --git a/moulinette/interfaces/__init__.py b/moulinette/interfaces/__init__.py
index 30ba8ae9..678c9526 100644
--- a/moulinette/interfaces/__init__.py
+++ b/moulinette/interfaces/__init__.py
@@ -1,7 +1,6 @@
 # -*- coding: utf-8 -*-
 
 import re
-import os
 import errno
 import logging
 import argparse
diff --git a/moulinette/interfaces/api.py b/moulinette/interfaces/api.py
index c102d9af..4ce66294 100644
--- a/moulinette/interfaces/api.py
+++ b/moulinette/interfaces/api.py
@@ -1,6 +1,5 @@
 # -*- coding: utf-8 -*-
 
-import os
 import re
 import errno
 import logging
diff --git a/moulinette/utils/filesystem.py b/moulinette/utils/filesystem.py
index fab5aa98..8d229e29 100644
--- a/moulinette/utils/filesystem.py
+++ b/moulinette/utils/filesystem.py
@@ -7,7 +7,6 @@ import grp
 from pwd import getpwnam
 
 from moulinette import m18n
-from moulinette.globals import CACHE_DIR
 from moulinette.core import MoulinetteError
 
 # Files & directories --------------------------------------------------
diff --git a/moulinette/utils/log.py b/moulinette/utils/log.py
index 47c13a1e..69eb62cf 100644
--- a/moulinette/utils/log.py
+++ b/moulinette/utils/log.py
@@ -1,7 +1,7 @@
 import os
 import logging
 
-# import all constant because other modules tries to important them from this
+# import all constants because other modules try to import them from this
 # module because SUCCESS is defined in this module
 from logging import (addLevelName, setLoggerClass, Logger, getLogger, NOTSET,
                      DEBUG, INFO, WARNING, ERROR, CRITICAL)
diff --git a/moulinette/utils/process.py b/moulinette/utils/process.py
index 299b96d5..5f1b0ddb 100644
--- a/moulinette/utils/process.py
+++ b/moulinette/utils/process.py
@@ -1,10 +1,7 @@
-import errno
 import time
 import subprocess
 import os
 
-from moulinette.core import MoulinetteError
-
 # This import is unused in this file. It will be deleted in future (W0611 PEP8),
 # but for the momment we keep it due to yunohost moulinette script that used
 # process.quote syntax to access this module !
@@ -60,13 +57,13 @@ def call_async_output(args, callback, **kwargs):
             raise ValueError('%s argument not allowed, '
                              'it will be overridden.' % a)
 
-    if "stdinfo" in kwargs and kwargs["stdinfo"] != None:
+    if "stdinfo" in kwargs and kwargs["stdinfo"] is not None:
         assert len(callback) == 3
         stdinfo = kwargs.pop("stdinfo")
         os.mkfifo(stdinfo, 0600)
         # Open stdinfo for reading (in a nonblocking way, i.e. even
         # if command does not write in the stdinfo pipe...)
-        stdinfo_f = os.open(stdinfo, os.O_RDONLY|os.O_NONBLOCK)
+        stdinfo_f = os.open(stdinfo, os.O_RDONLY | os.O_NONBLOCK)
     else:
         kwargs.pop("stdinfo")
         stdinfo = None