I don't think it's safe to use map.iteritems() in the various poll
routines.  I got some errors "dictionary changed size during
iteration" when running ZEO tests on machine while doing heavy
forground work in another window, and thinking about it, I believe
that it should be okay if readable() or writable() modifies the map.

I also finally made all the spacing conform to the Python style guide:
no space between a function/method name and the following left
parenthesis (fixed lots of occurrences), spaces around assignment
operators (fixed a few, always of the form "map=..."), and a blank
line between the class statement and the first method definition (a
few).
diff --git a/Lib/asyncore.py b/Lib/asyncore.py
index 180a189..e491f4d 100644
--- a/Lib/asyncore.py
+++ b/Lib/asyncore.py
@@ -90,12 +90,12 @@
     except:
         obj.handle_error()
 
-def poll (timeout=0.0, map=None):
+def poll(timeout=0.0, map=None):
     if map is None:
         map = socket_map
     if map:
         r = []; w = []; e = []
-        for fd, obj in map.iteritems():
+        for fd, obj in map.items():
             if obj.readable():
                 r.append(fd)
             if obj.writable():
@@ -118,40 +118,40 @@
                 continue
             write(obj)
 
-def poll2 (timeout=0.0, map=None):
+def poll2(timeout=0.0, map=None):
     import poll
     if map is None:
-        map=socket_map
+        map = socket_map
     if timeout is not None:
         # timeout is in milliseconds
         timeout = int(timeout*1000)
     if map:
         l = []
-        for fd, obj in map.iteritems():
+        for fd, obj in map.items():
             flags = 0
             if obj.readable():
                 flags = poll.POLLIN
             if obj.writable():
                 flags = flags | poll.POLLOUT
             if flags:
-                l.append ((fd, flags))
-        r = poll.poll (l, timeout)
+                l.append((fd, flags))
+        r = poll.poll(l, timeout)
         for fd, flags in r:
             obj = map.get(fd)
             if obj is None:
                 continue
             readwrite(obj, flags)
 
-def poll3 (timeout=0.0, map=None):
+def poll3(timeout=0.0, map=None):
     # Use the poll() support added to the select module in Python 2.0
     if map is None:
-        map=socket_map
+        map = socket_map
     if timeout is not None:
         # timeout is in milliseconds
         timeout = int(timeout*1000)
     pollster = select.poll()
     if map:
-        for fd, obj in map.iteritems():
+        for fd, obj in map.items():
             flags = 0
             if obj.readable():
                 flags = select.POLLIN
@@ -160,7 +160,7 @@
             if flags:
                 pollster.register(fd, flags)
         try:
-            r = pollster.poll (timeout)
+            r = pollster.poll(timeout)
         except select.error, err:
             if err[0] != EINTR:
                 raise
@@ -171,12 +171,12 @@
                 continue
             readwrite(obj, flags)
 
-def loop (timeout=30.0, use_poll=0, map=None):
+def loop(timeout=30.0, use_poll=0, map=None):
     if map is None:
         map = socket_map
 
     if use_poll:
-        if hasattr (select, 'poll'):
+        if hasattr(select, 'poll'):
             poll_fun = poll3
         else:
             poll_fun = poll2
@@ -184,20 +184,21 @@
         poll_fun = poll
 
     while map:
-        poll_fun (timeout, map)
+        poll_fun(timeout, map)
 
 class dispatcher:
+
     debug = 0
     connected = 0
     accepting = 0
     closing = 0
     addr = None
 
-    def __init__ (self, sock=None, map=None):
+    def __init__(self, sock=None, map=None):
         if sock:
-            self.set_socket (sock, map)
+            self.set_socket(sock, map)
             # I think it should inherit this anyway
-            self.socket.setblocking (0)
+            self.socket.setblocking(0)
             self.connected = 1
             # XXX Does the constructor require that the socket passed
             # be connected?
@@ -209,53 +210,53 @@
         else:
             self.socket = None
 
-    def __repr__ (self):
+    def __repr__(self):
         status = [self.__class__.__module__+"."+self.__class__.__name__]
         if self.accepting and self.addr:
-            status.append ('listening')
+            status.append('listening')
         elif self.connected:
-            status.append ('connected')
+            status.append('connected')
         if self.addr is not None:
             try:
-                status.append ('%s:%d' % self.addr)
+                status.append('%s:%d' % self.addr)
             except TypeError:
-                status.append (repr(self.addr))
-        return '<%s at %#x>' % (' '.join (status), id (self))
+                status.append(repr(self.addr))
+        return '<%s at %#x>' % (' '.join(status), id(self))
 
-    def add_channel (self, map=None):
-        #self.log_info ('adding channel %s' % self)
+    def add_channel(self, map=None):
+        #self.log_info('adding channel %s' % self)
         if map is None:
-            map=socket_map
+            map = socket_map
         map [self._fileno] = self
 
-    def del_channel (self, map=None):
+    def del_channel(self, map=None):
         fd = self._fileno
         if map is None:
-            map=socket_map
-        if map.has_key (fd):
-            #self.log_info ('closing channel %d:%s' % (fd, self))
+            map = socket_map
+        if map.has_key(fd):
+            #self.log_info('closing channel %d:%s' % (fd, self))
             del map [fd]
 
-    def create_socket (self, family, type):
+    def create_socket(self, family, type):
         self.family_and_type = family, type
-        self.socket = socket.socket (family, type)
+        self.socket = socket.socket(family, type)
         self.socket.setblocking(0)
         self._fileno = self.socket.fileno()
         self.add_channel()
 
-    def set_socket (self, sock, map=None):
+    def set_socket(self, sock, map=None):
         self.socket = sock
 ##        self.__dict__['socket'] = sock
         self._fileno = sock.fileno()
-        self.add_channel (map)
+        self.add_channel(map)
 
-    def set_reuse_addr (self):
+    def set_reuse_addr(self):
         # try to re-use a server port if possible
         try:
-            self.socket.setsockopt (
+            self.socket.setsockopt(
                 socket.SOL_SOCKET, socket.SO_REUSEADDR,
-                self.socket.getsockopt (socket.SOL_SOCKET,
-                                        socket.SO_REUSEADDR) | 1
+                self.socket.getsockopt(socket.SOL_SOCKET,
+                                       socket.SO_REUSEADDR) | 1
                 )
         except socket.error:
             pass
@@ -266,33 +267,33 @@
     # to pass to select().
     # ==================================================
 
-    def readable (self):
+    def readable(self):
         return True
 
     if os.name == 'mac':
         # The macintosh will select a listening socket for
         # write if you let it.  What might this mean?
-        def writable (self):
+        def writable(self):
             return not self.accepting
     else:
-        def writable (self):
+        def writable(self):
             return True
 
     # ==================================================
     # socket object methods.
     # ==================================================
 
-    def listen (self, num):
+    def listen(self, num):
         self.accepting = 1
         if os.name == 'nt' and num > 5:
             num = 1
-        return self.socket.listen (num)
+        return self.socket.listen(num)
 
-    def bind (self, addr):
+    def bind(self, addr):
         self.addr = addr
-        return self.socket.bind (addr)
+        return self.socket.bind(addr)
 
-    def connect (self, address):
+    def connect(self, address):
         self.connected = 0
         err = self.socket.connect_ex(address)
         if err in (EINPROGRESS, EALREADY, EWOULDBLOCK):
@@ -304,7 +305,7 @@
         else:
             raise socket.error, err
 
-    def accept (self):
+    def accept(self):
         # XXX can return either an address pair or None
         try:
             conn, addr = self.socket.accept()
@@ -315,9 +316,9 @@
             else:
                 raise socket.error, why
 
-    def send (self, data):
+    def send(self, data):
         try:
-            result = self.socket.send (data)
+            result = self.socket.send(data)
             return result
         except socket.error, why:
             if why[0] == EWOULDBLOCK:
@@ -326,9 +327,9 @@
                 raise socket.error, why
             return 0
 
-    def recv (self, buffer_size):
+    def recv(self, buffer_size):
         try:
-            data = self.socket.recv (buffer_size)
+            data = self.socket.recv(buffer_size)
             if not data:
                 # a closed connection is indicated by signaling
                 # a read condition, and having recv() return 0.
@@ -344,27 +345,27 @@
             else:
                 raise socket.error, why
 
-    def close (self):
+    def close(self):
         self.del_channel()
         self.socket.close()
 
     # cheap inheritance, used to pass all other attribute
     # references to the underlying socket object.
-    def __getattr__ (self, attr):
-        return getattr (self.socket, attr)
+    def __getattr__(self, attr):
+        return getattr(self.socket, attr)
 
     # log and log_info maybe overriden to provide more sophisitcated
     # logging and warning methods. In general, log is for 'hit' logging
     # and 'log_info' is for informational, warning and error logging.
 
-    def log (self, message):
-        sys.stderr.write ('log: %s\n' % str(message))
+    def log(self, message):
+        sys.stderr.write('log: %s\n' % str(message))
 
-    def log_info (self, message, type='info'):
+    def log_info(self, message, type='info'):
         if __debug__ or type != 'info':
             print '%s: %s' % (type, message)
 
-    def handle_read_event (self):
+    def handle_read_event(self):
         if self.accepting:
             # for an accepting socket, getting a read implies
             # that we are connected
@@ -378,26 +379,26 @@
         else:
             self.handle_read()
 
-    def handle_write_event (self):
+    def handle_write_event(self):
         # getting a write implies that we are connected
         if not self.connected:
             self.handle_connect()
             self.connected = 1
         self.handle_write()
 
-    def handle_expt_event (self):
+    def handle_expt_event(self):
         self.handle_expt()
 
-    def handle_error (self):
+    def handle_error(self):
         nil, t, v, tbinfo = compact_traceback()
 
         # sometimes a user repr method will crash.
         try:
-            self_repr = repr (self)
+            self_repr = repr(self)
         except:
-            self_repr = '<__repr__ (self) failed for object at %0x>' % id(self)
+            self_repr = '<__repr__(self) failed for object at %0x>' % id(self)
 
-        self.log_info (
+        self.log_info(
             'uncaptured python exception, closing channel %s (%s:%s %s)' % (
                 self_repr,
                 t,
@@ -408,23 +409,23 @@
             )
         self.close()
 
-    def handle_expt (self):
-        self.log_info ('unhandled exception', 'warning')
+    def handle_expt(self):
+        self.log_info('unhandled exception', 'warning')
 
-    def handle_read (self):
-        self.log_info ('unhandled read event', 'warning')
+    def handle_read(self):
+        self.log_info('unhandled read event', 'warning')
 
-    def handle_write (self):
-        self.log_info ('unhandled write event', 'warning')
+    def handle_write(self):
+        self.log_info('unhandled write event', 'warning')
 
-    def handle_connect (self):
-        self.log_info ('unhandled connect event', 'warning')
+    def handle_connect(self):
+        self.log_info('unhandled connect event', 'warning')
 
-    def handle_accept (self):
-        self.log_info ('unhandled accept event', 'warning')
+    def handle_accept(self):
+        self.log_info('unhandled accept event', 'warning')
 
-    def handle_close (self):
-        self.log_info ('unhandled close event', 'warning')
+    def handle_close(self):
+        self.log_info('unhandled close event', 'warning')
         self.close()
 
 # ---------------------------------------------------------------------------
@@ -432,25 +433,26 @@
 # [for more sophisticated usage use asynchat.async_chat]
 # ---------------------------------------------------------------------------
 
-class dispatcher_with_send (dispatcher):
-    def __init__ (self, sock=None):
-        dispatcher.__init__ (self, sock)
+class dispatcher_with_send(dispatcher):
+
+    def __init__(self, sock=None):
+        dispatcher.__init__(self, sock)
         self.out_buffer = ''
 
-    def initiate_send (self):
+    def initiate_send(self):
         num_sent = 0
-        num_sent = dispatcher.send (self, self.out_buffer[:512])
+        num_sent = dispatcher.send(self, self.out_buffer[:512])
         self.out_buffer = self.out_buffer[num_sent:]
 
-    def handle_write (self):
+    def handle_write(self):
         self.initiate_send()
 
-    def writable (self):
+    def writable(self):
         return (not self.connected) or len(self.out_buffer)
 
-    def send (self, data):
+    def send(self, data):
         if self.debug:
-            self.log_info ('sending %s' % repr(data))
+            self.log_info('sending %s' % repr(data))
         self.out_buffer = self.out_buffer + data
         self.initiate_send()
 
@@ -458,11 +460,11 @@
 # used for debugging.
 # ---------------------------------------------------------------------------
 
-def compact_traceback ():
+def compact_traceback():
     t,v,tb = sys.exc_info()
     tbinfo = []
     while 1:
-        tbinfo.append ((
+        tbinfo.append((
             tb.tb_frame.f_code.co_filename,
             tb.tb_frame.f_code.co_name,
             str(tb.tb_lineno)
@@ -478,9 +480,9 @@
     info = '[' + '] ['.join(map(lambda x: '|'.join(x), tbinfo)) + ']'
     return (file, function, line), t, v, info
 
-def close_all (map=None):
+def close_all(map=None):
     if map is None:
-        map=socket_map
+        map = socket_map
     for x in map.values():
         x.socket.close()
     map.clear()
@@ -504,35 +506,37 @@
     class file_wrapper:
         # here we override just enough to make a file
         # look like a socket for the purposes of asyncore.
-        def __init__ (self, fd):
+
+        def __init__(self, fd):
             self.fd = fd
 
-        def recv (self, *args):
+        def recv(self, *args):
             return os.read(self.fd, *args)
 
-        def send (self, *args):
+        def send(self, *args):
             return os.write(self.fd, *args)
 
         read = recv
         write = send
 
-        def close (self):
-            return os.close (self.fd)
+        def close(self):
+            return os.close(self.fd)
 
-        def fileno (self):
+        def fileno(self):
             return self.fd
 
-    class file_dispatcher (dispatcher):
-        def __init__ (self, fd):
-            dispatcher.__init__ (self)
+    class file_dispatcher(dispatcher):
+
+        def __init__(self, fd):
+            dispatcher.__init__(self)
             self.connected = 1
             # set it to non-blocking mode
-            flags = fcntl.fcntl (fd, fcntl.F_GETFL, 0)
+            flags = fcntl.fcntl(fd, fcntl.F_GETFL, 0)
             flags = flags | os.O_NONBLOCK
-            fcntl.fcntl (fd, fcntl.F_SETFL, flags)
-            self.set_file (fd)
+            fcntl.fcntl(fd, fcntl.F_SETFL, flags)
+            self.set_file(fd)
 
-        def set_file (self, fd):
+        def set_file(self, fd):
             self._fileno = fd
-            self.socket = file_wrapper (fd)
+            self.socket = file_wrapper(fd)
             self.add_channel()