diff --git a/powerline/lib/file_watcher.py b/powerline/lib/file_watcher.py
index 34616e90..426e168d 100644
--- a/powerline/lib/file_watcher.py
+++ b/powerline/lib/file_watcher.py
@@ -12,8 +12,8 @@ from threading import RLock
 from powerline.lib.monotonic import monotonic
 from powerline.lib.inotify import INotify, INotifyError
 
-class INotifyWatch(INotify):
 
+class INotifyWatch(INotify):
 	is_stat_based = False
 
 	def __init__(self, expire_time=10):
diff --git a/powerline/lib/inotify.py b/powerline/lib/inotify.py
index ecfdd1f8..1b58d49a 100644
--- a/powerline/lib/inotify.py
+++ b/powerline/lib/inotify.py
@@ -4,13 +4,18 @@ from __future__ import unicode_literals, absolute_import
 __copyright__ = '2013, Kovid Goyal <kovid at kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-import sys, os, errno
+import sys
+import os
+import errno
+
 
 class INotifyError(Exception):
 	pass
 
+
 _inotify = None
 
+
 def load_inotify():
 	''' Initialize the inotify library '''
 	global _inotify
@@ -53,8 +58,8 @@ def load_inotify():
 		_inotify = (init1, add_watch, rm_watch, read)
 	return _inotify
 
-class INotify(object):
 
+class INotify(object):
 	# See <sys/inotify.h> for the flags defined below
 
 	# Supported events suitable for MASK parameter of INOTIFY_ADD_WATCH.
@@ -98,7 +103,8 @@ class INotify(object):
 	NONBLOCK = 0x800
 
 	def __init__(self, cloexec=True, nonblock=True):
-		import ctypes, struct
+		import ctypes
+		import struct
 		self._init1, self._add_watch, self._rm_watch, self._read = load_inotify()
 		flags = 0
 		if cloexec:
@@ -164,12 +170,9 @@ class INotify(object):
 			pos += self.hdr.size
 			name = None
 			if get_name:
-				name = raw[pos:pos+name_len].rstrip(b'\0').decode(self.fenc)
+				name = raw[pos:pos + name_len].rstrip(b'\0').decode(self.fenc)
 			pos += name_len
 			self.process_event(wd, mask, cookie, name)
 
 	def process_event(self, *args):
 		raise NotImplementedError()
-
-
-
diff --git a/powerline/lib/tree_watcher.py b/powerline/lib/tree_watcher.py
index 1d2070c5..e345d286 100644
--- a/powerline/lib/tree_watcher.py
+++ b/powerline/lib/tree_watcher.py
@@ -1,26 +1,28 @@
-#!/usr/bin/env python
 # vim:fileencoding=UTF-8:noet
 from __future__ import (unicode_literals, absolute_import, print_function)
 
 __copyright__ = '2013, Kovid Goyal <kovid at kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-import sys, os, errno
+import sys
+import os
+import errno
 from time import sleep
 from powerline.lib.monotonic import monotonic
 
 from powerline.lib.inotify import INotify, INotifyError
 
+
 class NoSuchDir(ValueError):
 	pass
 
-class DirTooLarge(ValueError):
 
+class DirTooLarge(ValueError):
 	def __init__(self, bdir):
-		ValueError.__init__(self, 'The directory %s is too large to monitor. Try increasing the value in /proc/sys/fs/inotify/max_user_watches'%bdir)
+		ValueError.__init__(self, 'The directory {0} is too large to monitor. Try increasing the value in /proc/sys/fs/inotify/max_user_watches'.format(bdir))
+
 
 class INotifyTreeWatcher(INotify):
-
 	is_dummy = False
 
 	def __init__(self, basedir):
@@ -49,13 +51,13 @@ class INotifyTreeWatcher(INotify):
 				# The entry could have been deleted between listdir() and
 				# add_watch().
 				if top_level:
-					raise NoSuchDir('The dir %s does not exist'%base)
+					raise NoSuchDir('The dir {0} does not exist'.format(base))
 				return
 			if e.errno == errno.EACCES:
 				# We silently ignore entries for which we dont have permission,
 				# unless they are the top level dir
 				if top_level:
-					raise NoSuchDir('You do not have permission to monitor %s'%base)
+					raise NoSuchDir('You do not have permission to monitor {0}'.format(base))
 				return
 			raise
 		else:
@@ -67,20 +69,22 @@ class INotifyTreeWatcher(INotify):
 						# The dir was deleted/replaced between the add_watch()
 						# and listdir()
 						if top_level:
-							raise NoSuchDir('The dir %s does not exist'%base)
+							raise NoSuchDir('The dir {0} does not exist'.format(base))
 						return
 					raise
 				for x in files:
 					self.add_watches(os.path.join(base, x), top_level=False)
 			elif top_level:
 				# The top level dir is a file, not good.
-				raise NoSuchDir('The dir %s does not exist'%base)
+				raise NoSuchDir('The dir {0} does not exist'.format(base))
 
 	def add_watch(self, path):
 		import ctypes
 		bpath = path if isinstance(path, bytes) else path.encode(self.fenc)
 		wd = self._add_watch(self._inotify_fd, ctypes.c_char_p(bpath),
-				self.DONT_FOLLOW | self.ONLYDIR | # Ignore symlinks and watch only directories
+				# Ignore symlinks and watch only directories
+				self.DONT_FOLLOW | self.ONLYDIR |
+
 				self.MODIFY | self.CREATE | self.DELETE |
 				self.MOVE_SELF | self.MOVED_FROM | self.MOVED_TO |
 				self.ATTRIB | self.MOVE_SELF | self.DELETE_SELF)
@@ -88,7 +92,7 @@ class INotifyTreeWatcher(INotify):
 			eno = ctypes.get_errno()
 			if eno == errno.ENOTDIR:
 				return False
-			raise OSError(eno, 'Failed to add watch for: %s: %s'%(path, self.os.strerror(eno)))
+			raise OSError(eno, 'Failed to add watch for: {0}: {1}'.format(path, self.os.strerror(eno)))
 		self.watched_dirs[path] = wd
 		self.watched_rmap[wd] = path
 		return True
@@ -122,8 +126,8 @@ class INotifyTreeWatcher(INotify):
 		self.modified = False
 		return ret
 
-class DummyTreeWatcher(object):
 
+class DummyTreeWatcher(object):
 	is_dummy = True
 
 	def __init__(self, basedir):
@@ -132,8 +136,8 @@ class DummyTreeWatcher(object):
 	def __call__(self):
 		return False
 
-class TreeWatcher(object):
 
+class TreeWatcher(object):
 	def __init__(self, expire_time=10):
 		self.watches = {}
 		self.last_query_times = {}
@@ -145,7 +149,7 @@ class TreeWatcher(object):
 			w = INotifyTreeWatcher(path)
 		except (INotifyError, DirTooLarge) as e:
 			if logger is not None:
-				logger.warn('Failed to watch path: %s with error: %s'%(path, e))
+				logger.warn('Failed to watch path: {0} with error: {1}'.format(path, e))
 			w = DummyTreeWatcher(path)
 		self.watches[path] = w
 		return w
@@ -193,5 +197,3 @@ if __name__ == '__main__':
 			sleep(1)
 	except KeyboardInterrupt:
 		raise SystemExit(0)
-
-
diff --git a/tests/test_lib.py b/tests/test_lib.py
index b51dac83..f903b323 100644
--- a/tests/test_lib.py
+++ b/tests/test_lib.py
@@ -38,8 +38,8 @@ class TestLib(TestCase):
 		self.assertEqual(humanize_bytes(1000000000, si_prefix=True), '1.00 GB')
 		self.assertEqual(humanize_bytes(1000000000, si_prefix=False), '953.7 MiB')
 
-class TestFilesystemWatchers(TestCase):
 
+class TestFilesystemWatchers(TestCase):
 	def do_test_for_change(self, watcher, path):
 		import time
 		st = time.time()
@@ -47,7 +47,7 @@ class TestFilesystemWatchers(TestCase):
 			if watcher(path):
 				return
 			time.sleep(0.1)
-		self.fail('The change to %s was not detected'%path)
+		self.fail('The change to {0} was not detected'.format(path))
 
 	def test_file_watcher(self):
 		from powerline.lib.file_watcher import create_file_watcher
@@ -107,9 +107,9 @@ class TestFilesystemWatchers(TestCase):
 		changed()
 		os.mkdir(subdir)
 		changed()
-		os.rename(subdir, subdir+'1')
+		os.rename(subdir, subdir + '1')
 		changed()
-		shutil.rmtree(subdir+'1')
+		shutil.rmtree(subdir + '1')
 		changed()
 		os.mkdir(subdir)
 		f = os.path.join(subdir, 'f')
@@ -118,7 +118,7 @@ class TestFilesystemWatchers(TestCase):
 		with open(f, 'a') as s:
 			s.write(' ')
 		changed()
-		os.rename(f, f+'1')
+		os.rename(f, f + '1')
 		changed()
 
 use_mercurial = use_bzr = sys.version_info < (3, 0)
@@ -192,6 +192,7 @@ HG_REPO = 'hg_repo' + os.environ.get('PYTHON', '')
 BZR_REPO = 'bzr_repo' + os.environ.get('PYTHON', '')
 INOTIFY_DIR = 'inotify' + os.environ.get('PYTHON', '')
 
+
 def setUpModule():
 	global old_cwd
 	global old_HGRCPATH
@@ -217,7 +218,6 @@ def setUpModule():
 	os.mkdir(INOTIFY_DIR)
 
 
-
 def tearDownModule():
 	global old_cwd
 	global old_HGRCPATH