Ways to slice a string?

Question

I have a string, example:

s = \"this is a string, a\"

Where a \',\' (comma) will always be the 3rd to the last character, aka

Answer 1

A couple of variants, using the "delete the last comma" rather than "delete third last character" are:

s[::-1].replace(",","",1)[::-1]

or

''.join(s.rsplit(",", 1))

But these are pretty ugly. Slightly better is:

a, _, b = s.rpartition(",")
s = a + b

This may be the best approach if you don't know the comma's position (except for last comma in string) and effectively need a "replace from right". However Anurag's answer is more pythonic for the "delete third last character".