import re


def _strip(s):
    """
    Strips AACR2 punctuation from a string.
    """
    if not s:
        return s
    # remove leading trailing whitespace
    s = s.strip()
    # the negative lookbehind (?<! [A-Z]) is to prevent removing trailing 
    # periods from initialized names, e.g. Zingerman, B. I.
    return re.sub(r'(?<! [A-Z]) ?[.;,/]$', '', s)