Python获取重定向输入

#!/usr/bin/env python
import fileinput

f_input = fileinput.input()
for line in f_input:
     print(line, end='')

chmod a+x filein.py

$ ls | ./filein.py          # Prints a directory listing to stdout.
$ ./filein.py /etc/passwd   # Reads /etc/passwd to stdout.
$ ./filein.py < /etc/passwd # Reads /etc/passwd to stdout.