Answer:
Regular expression:
"^[^[^\w\s]|_]*[^\w\s]|_[^[^\w\s]|_]+[^\w\s]|_[^[^\w\s]|_]*$"
Explanation:
The regular expression has the following parts:
i) [^\w\s]|_ - expression to match any punctuation mark
ii) ^[^[^\w\s]|_] -
iii) *[^\w\s]|_ -
iv) [^[^\w\s]|_] -
v) +[^\w\s]|_ -
vi) [^[^\w\s]|_]*$" -