[英]Manipulating stdin and redirect to stdout in Python
I'm trying to write a simple python script where 我正在尝试编写一个简单的python脚本,其中
I only have the part where it takes the values from stdin and looks for the matching words, I'm a bit stuck after that. 我只有一部分从stdin中获取值并寻找匹配的单词,在那之后我有点卡住了。
import re
import sys
for line in sys.stdin:
matchObj = re.search(r'<something>(.*)</something>',line)
if matchObj:
oldWord = matchObj.group(1)
print oldWord
Contents of foo foo的内容
<something>REPLACEME</something>
<blah>UNTOUCH</blah>
Ideally if I run this command 理想情况下,如果我运行此命令
cat foo | ./test.py
I would get something like this 我会得到这样的东西
<something>NEWWORD</something
<blah>UNTOUCH</blah>
Are you looking for re.sub ? 您在寻找re.sub吗?
import re
import sys
for line in sys.stdin:
sys.stdout.write(re.sub(r'(<something>)REPLACEME(</something>)',
r'\1NEWWORD\2',
line))
Running the above on your example data: 在示例数据上运行以上代码:
$ echo '<something>REPLACEME</something>\n<something>UNTOUCH</something>' | python2 test.py
<something>NEWWORD</something>
<blah>UNTOUCH</blah>
Note that parsing XML with regular expressions is probably a bad idea. 请注意,使用正则表达式解析XML可能不是一个好主意。 The Python standard library comes with a number of XML modules .
Python标准库带有许多XML模块 。
Here's an example: 这是一个例子:
import sys
import xml.etree.ElementTree
tree = xml.etree.ElementTree.parse(sys.stdin)
root = tree.getroot()
for node in root.iter('something'):
if node.text == 'REPLACEME':
node.text == 'NEWWORD'
tree.write(sys.stdout)
The above would work just the same: 上面的工作原理是一样的:
$ echo '<root><something>REPLACEME</something>\n<blah>UNTOUCH</blah></root>' | python2 test.py
<root><something>REPLACEME</something>
<blah>UNTOUCH</blah></root>
firs if you run cat foo | ./test.py
如果您运行
cat foo | ./test.py
则将cat foo | ./test.py
cat foo | ./test.py
you got test.py: command not found
, you need to run this : cat foo |python ./test.py
. cat foo | ./test.py
您test.py: command not found
,您需要运行以下命令: cat foo |python ./test.py
。
then the output of your code will be : 那么您的代码输出将是:
REPLACEME
but for the output that you want, you need to use re.sub()
: 但是对于所需的输出,您需要使用
re.sub()
:
import re
import sys
for line in sys.stdin:
matchObj = re.sub(r'<something>(.*)</something>','<something>NEWWORD</something>',line)
if matchObj:
print matchObj
output : 输出:
<something>NEWWORD</something>
<blah>UNTOUCH</blah>
Also as a pythonic way you can use The ElementTree XML API
另外,作为Python方式,您可以使用
ElementTree XML API
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