我对Python很陌生,对stdin stdout方法甚至更新.不过,我需要使我的脚本可用于UNIX命令,以便例如使用我的脚本一次处理2个输入文件.

该脚本与命令行参数完美配合：

newlist = []

def f1()

....

def f2(input_file):

vol_id = sys.argv[3]

for line in input_file:

if ... :

line = line.replace('abc','def')

line = line.replace('id', 'id'+vol_id)

....

newlist.append(line)

return newlist

def main():

if len(sys.argv) < 4:

print 'usage: ./myscript.py [file_in... file_out... volume_id]'

sys.exit(1)

else:

filename = sys.argv[1]

filename_out = sys.argv[2]

tree = etree.parse(filename)

extract(tree)

input_file = open(filename, 'rU')

change_class(input_file)

file_new = open(filename_out, 'w')

for x in newlist:

if '

' in x:

x = x.replace('

', '')

print>>file_new, x

当我尝试向其添加stdin stdout时,首先遇到一个问题,即首先读取相同的输入文件,并且由于这个原因进行了一些修改,因此实际上只能打开一次.这是我修改过的main()：

filename = sys.argv[1]

filename_out = sys.argv[2]

if filename == '-':

filename = sys.stdin

else:

input_file = open(filename, 'rU')

if filename_out == '-':

filename_out = sys.stdout

file_new = filename_out

else:

file_new = open(filename_out, 'w')

input_file = open(filename, 'rU')

tree = etree.fromstring(input_file)

extract(tree)

change_class(input_file)

for x in newlist:

if '

' in x:

x = x.replace('

', '')

print>>file_new, x

然后我像这样运行我的脚本：

./myscript.py–volumeid输出文件

我得到了这个错误信息：

Traceback (most recent call last):

File "./myscript.py", line 191, in

main()

File "./myscript.py", line 175, in main

input_file = open(filename, 'rU')

TypeError: coercing to Unicode: need string or buffer, file found

我究竟做错了什么？