Need to find 2 strings using regex with multiple lines of text between them and insert replacement text

Question

I need perform a regular expression find and replace, many times in a large html file.

The first string to find is the following:

(?-i)(<p class=.+\r\n.+)([\d]{2}/[\d]{2}/[\d]{4})(((.+\r\n)+?)(.+>))(MIR)

The second string to find is the next occurrence of:

"Times New Roman"'>MIR

My objective is to insert the date group ([\d]{2}/[\d]{2}/[\d]{4}) into the second string, just before the "MIR"

My attempts to do this were unsuccessful.

The search string I came up with was this:

(?-i)())(MIR)((.+\r\n)+?)((.+)?>)(MIR)

The replacement string I came up with was this:

\1\2\3\7\8\10\2< br />\12

It does not work.

I need to do many such find and replace actions in the html file.

Any help you could give me would be much appreciated.

Marc

Answer 1

Try it like with the following pattern:

(<p class=.+\n.+)([\d]{2}/[\d]{2}/[\d]{4})(?:((.+\n)+?)(.+>))(MIR)

and substitution

\1\2\3\4\5\2< br />\6

Sample Code:

import re
regex = r"(<p class=.+\n.+)([\d]{2}/[\d]{2}/[\d]{4})(?:((.+\n)+?)(.+>))(MIR)"
subst = "\\1\\2\\3\\4\\5\\2< br />\\6"

# You can manually specify the number of replacements by changing the 4th argument
result = re.sub(regex, subst, test_str, 0)

if result:
    print (result)

Online demo.