我对 Python 很陌生,甚至对 stdin stdout 方法也很陌生。尽管如此,我需要使我的脚本可用于 UNIX 命令,以便可以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 '\n' in x:
x = x.replace('\n', '')
print>>file_new, x
当我尝试向其中添加 stdin stdout 时,我首先遇到了读取相同输入文件的问题,因此做了一些更改,以便它实际上只打开一次。这是我修改后的 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 '\n' in x:
x = x.replace('\n', '')
print>>file_new, x
然后我像这样运行我的脚本:
./myscript.py--volumeid输出文件
我收到此错误消息:
Traceback (most recent call last):
File "./myscript.py", line 191, in <module>
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?