在python中，如何检查标准输入流（sys.stdin）的结尾并对此做一些特殊的操作 [英] In python, how to check the end of standard input streams (sys.stdin) and do something special on that

问题描述

我想执行以下操作：

for line in sys.stdin:
    do_something()
    if is **END OF StdIn**:
        do_something_special()

经过几次尝试，现在我正在做这：

After a few tries, for now I am doing this:

while True:
    try:
        line = sys.stdin.next()
        print line,
    except StopIteration:
        print 'EOF!'
        break

：

while True:
    line = sys.stdin.readline()
    if not line:
        print 'EOF!'
        break
    print line,

我认为上述两种方式非常相似。我想知道是否有一种更优雅的（pythonic）方法来做到这一点？

I think both above ways are very similar. I want to know is there a more elegant (pythonic) way to do this?

我首先尝试从 for 循环的内部或外部捕获 StopIteration ，但是我很快意识到，由于 StopIteration 例外是内置 for 循环本身，以下两个代码段均无效

I first tried to catch the StopIteration from inside or outside of a for loop, but I soon realize that since the StopIteration exception is build into for loop itself, both following code snippet didn't work.

try:
    for line in sys.stdin:
        print line,
except StopIteration:
    print 'EOF'

或

for line in sys.stdin:
    try:
        print line,
    except StopIteration:
        print 'EOF'

推荐答案

for line in sys.stdin:
    do_whatever()
# End of stream!
do_whatever_else()

就是这么简单。

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