Inverse Match in Regex-CodePudding

I have a string

<img width="24" src="https://someurl.com" height="24" alt="FirstName LastName" id="ember44" > id="ember44" >

In the RegEx I need to select everything except

alt="FirstName LastName"

Tried some kind of expression

alt. (?!alt)

but still not in place. Thank you in advance!

CodePudding user response：

Instead of trying to match everything that isn't your "anti-search" string, how about replacing that string with nothing?

s = """<img width="24" src="https://someurl.com" height="24" alt="FirstName LastName" id="ember44" > id="ember44" >"""

s_new = re.sub(r'alt=\"[^\"] \"\s ', '', s)
# '<img width="24" src="https://someurl.com" height="24" id="ember44" > id="ember44" >'

Explanation (Try online):

alt=\"[^\"] \"\s 
-----------------

alt=\"       \"     : Literally alt=, followed by quotes
      [^\"]         : One or more non-quote characters
               \s   : One or more whitespace

CodePudding user response：

Well, in order to invert a regex, you could use re.sub() which takes 3 required arguments. a pattern, replacement, and a original string.

So, you could invert like this

import re

s = '<img width="24" src="https://someurl.com" height="24" alt="FirstName LastName" id="ember44" > id="ember44" >'

pattern = r'alt=".*?"'
without_alt = re.sub(pattern, '', s)
print(without_alt)