diff --git a/thefuck/rules/docker_not_command.py b/thefuck/rules/docker_not_command.py
index d866ee27..1c7e84c6 100644
--- a/thefuck/rules/docker_not_command.py
+++ b/thefuck/rules/docker_not_command.py
@@ -1,7 +1,7 @@
 from itertools import dropwhile, takewhile, islice
 import re
 import subprocess
-from thefuck.utils import get_closest, sudo_support, replace_argument, replace_command
+from thefuck.utils import sudo_support, replace_command
 
 
 @sudo_support
diff --git a/thefuck/rules/git_add.py b/thefuck/rules/git_add.py
index 10415d91..cb92e804 100644
--- a/thefuck/rules/git_add.py
+++ b/thefuck/rules/git_add.py
@@ -12,7 +12,7 @@ def match(command, settings):
 def get_new_command(command, settings):
     missing_file = re.findall(
             r"error: pathspec '([^']*)' "
-            "did not match any file\(s\) known to git.", command.stderr)[0]
+            r"did not match any file\(s\) known to git.", command.stderr)[0]
 
     formatme = shells.and_('git add -- {}', '{}')
     return formatme.format(missing_file, command.script)
diff --git a/thefuck/rules/git_checkout.py b/thefuck/rules/git_checkout.py
index afff835a..b883fca6 100644
--- a/thefuck/rules/git_checkout.py
+++ b/thefuck/rules/git_checkout.py
@@ -27,7 +27,7 @@ def get_branches():
 def get_new_command(command, settings):
     missing_file = re.findall(
         r"error: pathspec '([^']*)' "
-        "did not match any file\(s\) known to git.", command.stderr)[0]
+        r"did not match any file\(s\) known to git.", command.stderr)[0]
     closest_branch = utils.get_closest(missing_file, get_branches(),
                                        fallback_to_first=False)
     if closest_branch:
diff --git a/thefuck/rules/ls_lah.py b/thefuck/rules/ls_lah.py
index 70f6baab..580744bb 100644
--- a/thefuck/rules/ls_lah.py
+++ b/thefuck/rules/ls_lah.py
@@ -1,7 +1,7 @@
 def match(command, settings):
     return (command.script == 'ls'
             or command.script.startswith('ls ')
-            and not ('ls -' in command.script))
+            and 'ls -' not in command.script)
 
 
 def get_new_command(command, settings):
diff --git a/thefuck/rules/tmux.py b/thefuck/rules/tmux.py
index d58ae37a..2ba446e3 100644
--- a/thefuck/rules/tmux.py
+++ b/thefuck/rules/tmux.py
@@ -1,4 +1,4 @@
-from thefuck.utils import get_closest, replace_command
+from thefuck.utils import replace_command
 import re
 
 
diff --git a/thefuck/rules/tsuru_not_command.py b/thefuck/rules/tsuru_not_command.py
index e3f1e4cf..86b4d15f 100644
--- a/thefuck/rules/tsuru_not_command.py
+++ b/thefuck/rules/tsuru_not_command.py
@@ -1,6 +1,5 @@
 import re
-from thefuck.utils import (get_closest, replace_argument,
-                           get_all_matched_commands, replace_command)
+from thefuck.utils import get_all_matched_commands, replace_command
 
 
 def match(command, settings):
diff --git a/thefuck/shells.py b/thefuck/shells.py
index 6c7a7baa..400d705f 100644
--- a/thefuck/shells.py
+++ b/thefuck/shells.py
@@ -216,7 +216,7 @@ class Tcsh(Generic):
         return u'#+{}\n{}\n'.format(int(time()), command_script)
 
 
-shells = defaultdict(lambda: Generic(), {
+shells = defaultdict(Generic, {
     'bash': Bash(),
     'fish': Fish(),
     'zsh': Zsh(),