[SOLVED] How can I find the last occurance of a dot not preceding with a slash?

How can I find the last occurance of a dot not preceding with a slash?

I'm trying to create a regex to find the last dot in a string not preceded by a slash.

r = MyLine.Text.Swap\ Numbered\ and\ Unnumbered\ List.From\ -\ -\ -\ to\ Numbered\ list\ 1\.\ 2\.\ 3\.\

What I want to find as match is "From\ -\ -\ -\ to\ Numbered\ list\ 1\.\ 2\.\ 3\.\"

I tried to reverse the string but that didn't work either re.findall(".*\\.(?!\\\)", r[::-1])

What did I wrong?

Solution

You might use a negative lookbehind matching a dot, and then assert that what is to the left is not a \ followed by a dot.

Then you could capture what comes after it in group 1 which would be returned by re.findall

.*\.(?<!\\\.)(.*)

See a regex demo and a Python demo

For example:

import re

pattern = r".*\.(?<!\\\.)(.*)"

r = "MyLine.Text.Swap\\ Numbered\\ and\\ Unnumbered\\ List.From\\ -\\ -\\ -\\ to\\ Numbered\\ list\\ 1\\.\\ 2\\.\\ 3\\.\\ "

matches = re.findall(pattern, r)
print(matches)

Output

['From\\ -\\ -\\ -\\ to\\ Numbered\\ list\\ 1\\.\\ 2\\.\\ 3\\.\\ ']