[英]python re.sub, only replace part of match
I am very new to python 我是python的新手
I need to match all cases by one regex expression and do a replacement. 我需要通过一个正则表达式匹配所有情况并进行替换。 this is a sample substring --> desired result:
这是一个示例子字符串 - >所需的结果:
<cross_sell id="123" sell_type="456"> --> <cross_sell>
i am trying to do this in my code: 我想在我的代码中这样做:
myString = re.sub(r'\<[A-Za-z0-9_]+(\s[A-Za-z0-9_="\s]+)', "", myString)
instead of replacing everything after <cross_sell
, it replaces everything and just returns '>'
而不是在
<cross_sell
之后替换所有内容,它会替换所有内容并返回'>'
is there a way for re.sub to replace only the capturing group instead of the entire pattern? 有没有办法让re.sub只替换捕获组而不是整个模式?
You can use substitution groups: 您可以使用替换组:
>>> my_string = '<cross_sell id="123" sell_type="456"> --> <cross_sell>'
>>> re.sub(r'(\<[A-Za-z0-9_]+)(\s[A-Za-z0-9_="\s]+)', r"\1", my_string)
'<cross_sell> --> <cross_sell>'
Notice I put the first group (the one you want to keep) in parenthesis and then I kept that in the output by using the "\\1"
modifier (first group) in the replacement string. 请注意,我将第一组(您要保留的组)放在括号中,然后通过在替换字符串中使用
"\\1"
修饰符(第一组)将其保留在输出中。
You can use a group reference to match the first word and a negated character class to match the rest of the string between <>
: 您可以使用组引用匹配第一个单词和否定字符类以匹配
<>
之间的其余字符串:
>>> s='<cross_sell id="123" sell_type="456">'
>>> re.sub(r'(\w+)[^>]+',r'\1',s)
'<cross_sell>'
\\w
is equal to [A-Za-z0-9_]
. \\w
等于[A-Za-z0-9_]
。
Since the input data is XML, you'd better parse it with an XML parser . 由于输入数据是XML,因此最好使用XML解析器对其进行解析 。
Built-in xml.etree.ElementTree
is one option: 内置的
xml.etree.ElementTree
是一个选项:
>>> import xml.etree.ElementTree as ET
>>> data = '<cross_sell id="123" sell_type="456"></cross_sell>'
>>> cross_sell = ET.fromstring(data)
>>> cross_sell.attrib = {}
>>> ET.tostring(cross_sell)
'<cross_sell />'
lxml.etree
is an another option. lxml.etree
是另一种选择。
below code tested under python 3.6 , without use group.. 下面的代码在python 3.6下测试,没有使用组..
test = '<cross_sell id="123" sell_type="456">'
resp = re.sub(r'\w+="\w+"' ,r'',test)
print (resp)
<cross_sell>
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