打印大量格式化数据时如何避免Broken Pipe错误？

我正在尝试打印我的格式的元组列表stdout。为此，我使用字符串格式 http://docs.python.org/2/library/string.html#string-formatting方法。一切工作正常，但是当我通过管道输出看到 第一行使用head命令一个IOError occurs.

这是我的代码：

# creating the data
data = []$
for i in range(0,  1000):                                            
  pid = 'pid%d' % i
  uid = 'uid%d' % i
  pname = 'pname%d' % i
  data.append( (pid, uid, pname) )

# find max leghed string for each field
pids, uids, pnames = zip(*data)
max_pid = len("%s" % max( pids) )
max_uid = len("%s" % max( uids) )
max_pname = len("%s" % max( pnames) )

# my template for the formatted strings
template = "{0:%d}\t{1:%d}\t{2:%d}" % (max_pid, max_uid, max_pname)

# print the formatted output to stdout
for pid, uid, pname in data:
  print template.format(pid, uid, pname)

这是运行命令后出现的错误：python myscript.py | head

Traceback (most recent call last):
  File "lala.py", line 16, in <module>
    print template.format(pid, uid, pname)
IOError: [Errno 32] Broken pipe

谁可以帮我这个事？

我试着把print in a try-except块来处理错误， 但之后控制台中又出现了另一条消息：

close failed in file object destructor:
sys.excepthook is missing
lost sys.stderr

我还尝试通过两个连续的立即刷新数据sys.stdout.write and sys.stdout.flush打电话，但什么也没发生..

head读取自stdout then closes它。这导致print如果失败，它会在内部写入sys.stdout，现已关闭。

您可以简单地catch the IOError并默默退出：

try:
    for pid, uid, pname in data:
        print template.format(pid, uid, pname)
except IOError:
    # stdout is closed, no point in continuing
    # Attempt to close them explicitly to prevent cleanup problems:
    try:
        sys.stdout.close()
    except IOError:
        pass
    try:
        sys.stderr.close()
    except IOError:
        pass