diff --git a/eventlet/api.py b/eventlet/api.py
index b266b51..ebe0d11 100644
--- a/eventlet/api.py
+++ b/eventlet/api.py
@@ -21,15 +21,20 @@ __all__ = [
 warnings.warn("eventlet.api is deprecated!  Nearly everything in it has moved "
     "to the eventlet module.", DeprecationWarning, stacklevel=2)
 
+
 def get_hub(*a, **kw):
     warnings.warn("eventlet.api.get_hub has moved to eventlet.hubs.get_hub",
         DeprecationWarning, stacklevel=2)
     return hubs.get_hub(*a, **kw)
+
+
 def get_default_hub(*a, **kw):
     warnings.warn("eventlet.api.get_default_hub has moved to"
         " eventlet.hubs.get_default_hub",
         DeprecationWarning, stacklevel=2)
     return hubs.get_default_hub(*a, **kw)
+
+
 def use_hub(*a, **kw):
     warnings.warn("eventlet.api.use_hub has moved to eventlet.hubs.use_hub",
         DeprecationWarning, stacklevel=2)
@@ -58,6 +63,7 @@ def tcp_listener(address, backlog=50):
     util.socket_bind_and_listen(socket, address, backlog=backlog)
     return socket
 
+
 def ssl_listener(address, certificate, private_key):
     """Listen on the given (ip, port) *address* with a TCP socket that
     can do SSL.  Primarily useful for unit tests, don't use in production.
@@ -78,6 +84,7 @@ def ssl_listener(address, certificate, private_key):
     socket.listen(50)
     return socket
 
+
 def connect_tcp(address, localaddr=None):
     """
     Create a TCP connection to address ``(host, port)`` and return the socket.
diff --git a/eventlet/green/thread.py b/eventlet/green/thread.py
index 9e15b8d..4a68ba8 100644
--- a/eventlet/green/thread.py
+++ b/eventlet/green/thread.py
@@ -4,22 +4,26 @@ from eventlet.support import greenlets as greenlet
 from eventlet import greenthread
 from eventlet.semaphore import Semaphore as LockType
 
+
 __patched__ = ['get_ident', 'start_new_thread', 'start_new', 'allocate_lock',
-               'allocate', 'exit', 'interrupt_main', 'stack_size', '_local', 
+               'allocate', 'exit', 'interrupt_main', 'stack_size', '_local',
                'LockType', '_count']
 
 error = __thread.error
 __threadcount = 0
 
+
 def _count():
     return __threadcount
 
+
 def get_ident(gr=None):
     if gr is None:
         return id(greenlet.getcurrent())
     else:
         return id(gr)
 
+
 def __thread_body(func, args, kwargs):
     global __threadcount
     __threadcount += 1
@@ -28,22 +32,30 @@ def __thread_body(func, args, kwargs):
     finally:
         __threadcount -= 1
 
-def start_new_thread(function, args=(), kwargs={}):
+
+def start_new_thread(function, args=(), kwargs=None):
+    kwargs = kwargs or {}
     g = greenthread.spawn_n(__thread_body, function, args, kwargs)
     return get_ident(g)
-    
+
+
 start_new = start_new_thread
 
+
 def allocate_lock(*a):
     return LockType(1)
 
+
 allocate = allocate_lock
 
+
 def exit():
     raise greenlet.GreenletExit
-    
+
+
 exit_thread = __thread.exit_thread
 
+
 def interrupt_main():
     curr = greenlet.getcurrent()
     if curr.parent and not curr.parent.dead:
@@ -51,6 +63,7 @@ def interrupt_main():
     else:
         raise KeyboardInterrupt()
 
+
 if hasattr(__thread, 'stack_size'):
     __original_stack_size__ = __thread.stack_size
     def stack_size(size=None):
diff --git a/eventlet/hubs/poll.py b/eventlet/hubs/poll.py
index 6284e72..233986e 100644
--- a/eventlet/hubs/poll.py
+++ b/eventlet/hubs/poll.py
@@ -13,6 +13,7 @@ EXC_MASK = select.POLLERR | select.POLLHUP
 READ_MASK = select.POLLIN | select.POLLPRI
 WRITE_MASK = select.POLLOUT
 
+
 class Hub(BaseHub):
     def __init__(self, clock=time.time):
         super(Hub, self).__init__(clock)
@@ -27,7 +28,7 @@ class Hub(BaseHub):
         listener = super(Hub, self).add(evtype, fileno, cb)
         self.register(fileno, new=True)
         return listener
-    
+
     def remove(self, listener):
         super(Hub, self).remove(listener)
         self.register(listener.fileno)
@@ -47,7 +48,7 @@ class Hub(BaseHub):
                         self.modify(fileno, mask)
                     except (IOError, OSError):
                         self.poll.register(fileno, mask)
-            else: 
+            else:
                 try:
                     self.poll.unregister(fileno)
                 except (KeyError, IOError, OSError):
@@ -108,7 +109,6 @@ class Hub(BaseHub):
             except:
                 self.squelch_exception(fileno, sys.exc_info())
                 clear_sys_exc_info()
-        
+
         if self.debug_blocking:
             self.block_detect_post()
-
diff --git a/eventlet/tpool.py b/eventlet/tpool.py
index f4075ac..e4e3a7b 100644
--- a/eventlet/tpool.py
+++ b/eventlet/tpool.py
@@ -44,6 +44,7 @@ def _signal_t2e():
     _wfile.write(_bytetosend)
     _wfile.flush()
 
+
 _reqq = None
 _rspq = None