What is a regex to match ONLY an empty string?

Question

There are lots of posts about regexs to match a potentially empty string, but I couldn\'t readily find any which provided a regex which only matched an emp

Answer 1

Another possible answer considering also the case that an empty string might contain several whitespace characters for example spaces,tabs,line break characters can be the folllowing pattern.

pattern = r"^(\s*)$"

This pattern matches if the string starts and ends with zero or more whitespace characters.

It was tested in Python 3