在无数据的无阻塞套接字的情况下，recv将抛出socket.error异常，并且异常的值将具有EAGAIN或EWOULDBLOCK的错误号。例：
import sysimport socketimport fcntl, osimport errnofrom time import sleeps = socket.socket(socket.AF_INET, socket.SOCK_STREAM)s.connect(('127.0.0.1',9999))fcntl.fcntl(s, fcntl.F_SETFL, os.O_NONBLOCK)while True: try: msg = s.recv(4096) except socket.error, e: err = e.args[0] if err == errno.EAGAIN or err == errno.EWOULDBLOCK: sleep(1) print 'No data available' continue else: # a "real" error occurred print e sys.exit(1) else: # got a message, do something :)在您通过
socket.settimeout(n)或通过超时启用了非阻塞行为的情况下，情况有所不同
socket.setblocking(False)。在这种情况下，仍会引发socket.error，但在超时的情况下，异常的伴随值始终是设置为“超时”的字符串。因此，要处理这种情况，您可以执行以下操作：
import sysimport socketfrom time import sleeps = socket.socket(socket.AF_INET, socket.SOCK_STREAM)s.connect(('127.0.0.1',9999))s.settimeout(2)while True: try: msg = s.recv(4096) except socket.timeout, e: err = e.args[0] # this next if/else is a bit redundant, but illustrates how the # timeout exception is setup if err == 'timed out': sleep(1) print 'recv timed out, retry later' continue else: print e sys.exit(1) except socket.error, e: # Something else happened, handle error, exit, etc. print e sys.exit(1) else: if len(msg) == 0: print 'orderly shutdown on server end' sys.exit(0) else: # got a message do something :)如评论中所述，这也是一种更可移植的解决方案，因为它不依赖于操作系统特定的功能来将套接字置于非阻塞模式。
有关更多详细信息，请参见recv（2）和python
socket。
